How do you know?
Is there a way to tell, on the phone (2.1/Eclair)? Or do you have to log in at your wireless carrier?
Do I understand this right, that if I am on Wi-Fi, any data usage is NOT counted against my data cap?
I'm capped at 5GB and I avoid YouTube and things involving streaming for this reason... but if I set my Wi-Fi network up at home (currently, it's strictly wired) it would be nice to do those things if it bypassed my 5GB cap. And I don't mind the cap, or at least I won't if my regular Facebook usage and trying out new apps on Market, and the random Opera Mini browsing doesn't add up to 5GB. If it does... well, I'll cross that bridge when I come to it.