I have been using my iPaq H3970 in conjunction with the Class 1 (100m)
MSI  USB dongle on my XP PC for the internet connection capability.

The iPaq has the ability to increase it's power, so I naturally assumed
that it too was a Class 1 device when set to maximum power. Sure enough,
it works at the far end of the garden some 90 feet distant (two
intervening brick/plaster walls and a conservatory).

I also have a Gigabyte bluetooth USB dongle, Class 2 (10m) for my
laptop. Today, I took the laptop setup for a walk - just to see how far
down the garden I could go. Result ? All the way to the end ! (I wasn't
expecting to get much further than the back door).

- I managed to download Adobe Acrobat Reader 6 (16Mb) without any
problems.

So the range seems to be at least as far as the strongest device's
range.

Roll on the summer !