Does anyone know how much O2 actually check for the above? That is, does anyone use the O2 Web bolt-on on another handset and regularly tether this to a computer, or do VoIP? Streaming audio/video (assuming they mean more than just the odd youtube clip), P2P or file-sharing aren't so important to me, but I would certainly like to use VoIP and tether occasionally.

I ask because I use O2 already for a GSM-only phone provided by my work, and it would be easier to stick with O2 if I upgrade to an N900.