We're no strangers to caps here in India. They're referred to as a "fair usage" policy. I used Networx for a while - it gave me excellent logs and graphs, until my ISP informed me that my uploads also count towards the cap. That's when I asked them to tell me where I could monitor my usage according to their specifications. Turns out that their site listed daily details of downloads and uploads - the best option simply because it tells me exactly how much I'm using according to the entity that's going to bill me.

The Belkin WiFi phone sounds like a good idea. The trouble with using an iPod touch would be the battery life with WiFi on. I've tried to browse for an hour so on my iPod Touch and it severely drains the battery. Why get a music player/gaming device if what you really need is a phone? Yup. Get the Belkin phone and subscribe to SkypeOut. I've been pretty satisfied with the call experience even when I've made international calls. Safest way to go IMO.