Got to looking at the data sheets for the chips, they are in fact designed to interface a microprocessor (or uC) to USB, and need addressing and commands sent to them (nevertheless they are pretty good, they do all the USB protocol donkey work for you AND were only 50c each...) but you can't just shove a few geiger counter pulses into them and get them out at the PC, not without something in between anyway.
Whereas using a serial interface (either via a USB to serial adapter or direct) would be easy - I'd envisage an 8-bit counter reporting its contents every second to the PC - that would let you count up to 60 x 256 =15360 counts per minute (some geiger tubes can do more than this but you would not want to be near that...). the PC could then display the results both instantaneously and over days / months / years etc.
Had a look - these cables are ok but (to my mind) fairly expensive (US26 a pop approx). You can sometimes pick up USB to serial cables for around $10. Maybe make the sevice serial, then you can connect using either serial or USB as you wish.
Funny, your comment reminded of another USB complaint...cable length. USB tops out around 16ft unless you use an "active link" cable with it's own power. Granted, RS232 or Parallel ports probably weren't used by most at such distances, but I recall many shared printers in an industrial setting I once worked. I suppose you'd run Ethernet for that these days since WiFi would likely succumb to interference.
You just reminded me of a USB mystery I had to solve a few years back. I was apparently near the power limit of the USB hub on my motherboard, and plugging in my iPod put it over the limit. At least Windows XP gave me a warning about a "power surge" on the hub, and then it disabled it.
Unplugging all USB devices and doing a power off-power on reboot did not restore the hub. After some googling, I learned the corrective action -- unplug the AC mains power, plug it back in and reboot, and THEN the USB hub came back to life.
Now I use an externally powered hub, which has the added advantage of being able to sit on my desk, where it is easier to reach.
I second the joystick port comment...it moved to the system board in the late 90s I think. USB is nice, but I for one recall its painful support debut in Windows 98, which required drivers and a reboot. That said, I don't miss losing my mouse in Windows if I happened to unplug that PS/2 cable by accident.
Regarding USB/RS232 converters...I've never run into one that doesn't require a driver and even read an article once that stated it was impossible to create a driverless one due to the required signaling conversions. There are many complaints in the DIY community about the limitations of these buggers at least, not to mention the smack in the face of having to spend $20 more just to interface that new microtroller with your "modern" PC since there is no RS232 port. Besides, I fondly remember using my parallel port in college to interface my Nintendo Powerglove with a customer version of Doom.
Finally, USB is just as complicated for novices IMHO. Loads of devices require drivers, e.g. 1TB WD Passport drives, and won't work without an install and a reboot, but sometimes you can get away without rebooting. Second, finding drivers automatically is fraught with issues in my experience, often resulting in a not-quite-compatible driver that either hangs your system or causes random issues. Third, if you have a driver or other system service that latches onto your portable drive, you may not be able to safely remove it without a reboot (Windows). Then there's the complexity of USB power management. With so many devices, especially one's that don't adhere to the USB power standards, you'll often find that shiny new device just "doesn't work" for no apparent reason and average users don't have Scotty to yell "I'm giving you all she's got Captain". This is especially true if you plug that power hungry drive into the same hub as your keyboard/mouse. Imagine their frustration when those two items inexplicably stop working. Can you say reboot?
Well - not all of the USB/RS232 converters are created equal. I had a cheap one ($25) I was using for an RS232 CLI port on an embedded system to a terminal emulator on a laptop. Weird things happened. A scope showed that, RS232 unplugged, the TX pin had a nice +/- 100v sine wave on it. Cannot remember if the sine was at 60Hz. Caused all sorts of interesting behaviors.
I can recommend the one from accesio - solid , reasonable price ($40). They even took one into their lab and looked at the TX line on a scope before I bought it.
I always put an RS232 port for a CLI on any embedded project, even if I need to bit-bang 1200 baud. Old-school works - KISS. Even if the system has USB.
I like the Atmel AT90USB chips if you are going to do a USB project.
Of course USB is complicated to deal with directly but with all the USB chips out there:
USB to digital I/O, USB to RS232, etc. (and their assoc. drivers) the hobby heads can usually get something working.
USB was invented not for the likes of us who CAN make RS232 work, but for your average user who just wants to plug and play. Fortunately it DOES work most of the time now. But remember the old Plug and Pray days of early PCI cards?
I once made a good bit of money fixing an RS232 interface for a guy who had a shoe pattern cutter. My PC supplier put me onto him and he was desperate. Alas, I've never been able to do that with USB....
I had a notebook with about twenty pages of wiring diagrams for various permutations of RS-232 printer type to computer type. It wasn't just one wiring diagram per page either. In the same notebook, I had the start/stop/parity bit notation and any dip switch settings. My tool box contained a couple of different break out boxes as well as couplers pre-wired with the most common combinations, and some LED boxes to conform that data was going one way or the other. I do not miss that.
It is a lot easier to use now though, that most uses follow the standard pretty strictly.
As far as USB goes, in most ways it's a monumental improvement. It does drive me nuts though when some devices can be plugged in at any time and others require that the driver be installed prior to plugging the device in.
I recall back in the early days of USB 1.0, one of the companies promoting the standard put together a demonstration where they daisy chained something like 128 devices to show the utility and power of the system. Real world use won't live up to that demo.