FYI, there's a T-Mobile plan for $30/mo with 5GB of data if you don't talk on the phone that much--it only offers 100 minutes of talk time.

This is the one I'm looking at. I make most of my calls via my PC using Google Voice anyways. Also they only throttle you when you go over (as opposed to charging you big overages).

I'm currently on a $30 T-Mobile Mothly4G plan on a Galaxy Nexus. The catch is that, in my area, T-Mobile's service isn't quite as good as Verizon's, who I was previously with.

And that's it. That is literally the only complaint I've had and, for $30 a month, I'm willing to live with that.

I've heard it repeated that the Nexus 4 can be used with T-Mobile prepaid, but can it be used with Virgin Mobile USA? VM looks to be $35/month rather than the $50/month that T-Mobile costs.

Virgin Mobile's rates are attractive, but unfortunately they're a Sprint subsidiary, and as such use CDMA. Nexus 4 is GSM, so your best bet is StraightTalk, T-Mobile, or other inexpensive prepaid GSM carriers. As others have said, check out T-Mobile's web-only $30/month option. It's about as close as you can get to what we've all been wanting: a data-only plan.

Also as far as I know VM doesn't let you "bring your own phone". You can supposedly fake a serial number (or whatever identifier they use) of another phone that you purchased, but that's unadvisable.

I hear that Simple Mobile and Straight Talk are valid options.

Virgin (Sprint) is CDMA; impossible.

I'm on the TMo $30 prepaid. It is awesome. HSPA+ is very fast and responsive. I'm in NYC though where I know they are particularly good.