USB 2.0 was released 2000 Kabouter.
The difference between USB 1.0 and 2.0 is the same difference between Network CAT5 10Mb and 100Mb ...
the difference is almost literally speed.
1.0 ~1.5Mb/s
2.0 ~150Mb/s
quite literally the difference, and very few things require the extra speed.
there isn't actually any way to find out the version past actually getting the manual and checking.
you however can goto My Computer -> Properties -> Hardware -> Device Manager ... and at the end double click on either the Root Hub or USB Port Driver;
Hub will give you Power Use & Driver will give you Bandwidth Use.
Bandwidth use for a 1.5Mb device on USB 1.0 is 40% Each.
So just find yourself a device you know will be highly demanding, like a printer or scanner.
Athlon64 FX-51 | 1.5Gb DDR2 PC3400 | GeForce FX 5900 Ultra 56.60 | DirectX9.1 SDK | Audigy2 | Windows XP 64-Bit