Yeah, I've done a fair bit of research regarding pricing and expiration of minutes, and T-mobile is the only one that has the bare bones I want with a decent network in my area (for $100, your minutes don't expire for one year). The only other company I'm even considering is Net10 ($100 for 180 days), which is a subsidiary of Tracfone, but I read some
customer reviews and got completely scared off Net10 and am now marginally scared of T-mobile.
Like I said, I have Skype unlimited to make calls from home, but I wanted the cell for the job search, for incoming calls, and to make calls when, say, my internet is down, there's a storm, or I'm on the road -- basically, to replace the home phone which is much more expensive and hardly used. (Skype can sometimes have feedback/echo issues, so I wouldn't want to use it to talk to an employer.) However, if the cell is going to be unreliable, than I"m better off just getting a Skype-in number (so I can receive incoming calls to my computer) and having an emergency cell for calling 911 (which my friend has already given me).
Thanks for the feedback, everyone, and I'd love to hear more input from actual users or friends of users of either of these companies.