Don't worry about a learning curve. Just buy a SIM and get started. Risk about $20. It's quite easy.

BTW: For more info, do a Power Search for key words tmobile and prepaid. You should find a thread that discusses this in detail.

@bandofbrothers:
Eh, it probably won't be that much of one. I -do- have a N770(which I upgraded with an 8GB SDHC, I might add), and IIRC maemo 5 is internally like Os2006/7(I.e. Debian based), so I shouldn't have much trouble tweaking it etc.
The phone side of things will be interesting, but so long as there is a simple way to dial a number and press "call", no worries there.

@geneven:
So long as I can get one of those Tmobile sims and it will -work- with my N900, I'm sure I won't have any trouble. And, from the responses, it looks like it will without issue.

I just bought a new Tmobile sim off ebay(Cause I'm -sure- it will be faster than off Nokia's own site, and a tad cheaper at $5.75). Only little glitch is that it doesn't come with an activation code. I did some googling however, and it seems all I will have to do is call Tmobile customer support and get them to give me a code... if I read things right.

If any of you see hurdles in my plan, please let me know.

-Rob

Just wondering how the wireless plan is working out. I'm currently with AT&T with my n900. I'd like maybe 200-500 minutes a month, unlimited texting & unlimited data. Being able to do this without a contract would be a plus. Would also like to get it for as little as possible (who wouldn't?) and don't mind switching providers if I need to - as long as I can keep my number.

Thanks!

Thread necromancy is not appreciated.
But... I might as well answer:
1. I ended up having to pay for a new sim+ activation code from T-mobile, which was shipped to me. After activating it, it worked fine.

Only recently have I figured out how to do internet with it - the pay-as-you-go plan allows you to buy $1.50/24hrs unliimited access, and you can subscribe right on your phone.
So far, it's working and I'm happy with it.

I have T-mobile prepaid which I use only very occasionally and never for the Internet (although as others have pointed out you can get access on a 24-hour basis). I have a Clearspot wimax modem (very small, http://www.clear.com) which I use for Internet access. It supports up to 8 wireless devices plus you can connect via usb (but I've never connected the N900 by usb). Clear is owned by Sprint and provides the 4G access for Sprint cell phones. But you don't need Sprint, just a Clear account.