I've been with o2 since the original iPhone came out and curently have an iPhone 4. I wasn't overly concerned with o2's data cap of 500MB as I couldn't download very much as I only get GPRS at work and at home. Normally I manage about 200-300MB. Since getting the iPhone in July, O2 had an unlimited data promotion, now thats over so I decied to check my data usage, I've somehow managed to use 487.67 MB of the 500MB with a week to go to the end of the month. I haven't noticed any change in my browsing habits or any change in 3G signal availability so why the sudden increase now unlimited data is gone?