Okay, laptop is back in service, impulse buy of pretty, pretty 22" widescreen LCD is worth every penny, and the Internet is fixed, following a complete router reboot and configuration. My graphics card was not the problem with my laptop, after all - it was either the LCD or the backlight, and either way, I'm able to bypass it by rebooting it with monitor attached (I didn't realize you had to restart it with monitor attached, and there's also a fin-F5 technique to add to my box of computer tricks...) The graphics card IS way underpowered (being 6 years old) and an upgrade will indeed be in the near future, but for now, I'm back in business and very relieved to be able to post things again. It was very surreal and disconnected to be able to view, read, delete, but not post to email, forums or forms. LJ still worked, sporadically, but not reliably. I can shop for a new machine at my leisure, not a mad panicked 'I gotta get orders out NOW' rush, at least. I looked at Dell's XP options (not hot), and have poked around a couple of other places, and I'm not sure yet what direction I'll end up going. (And yes, these were totally unrelated problems, Internet and laptop, they just happened to occur on the same day, thank you, oh god of technology and your twisted sense of humor...)
A Mac is not out of the question, but still somewhat unlikely. I'll be doing some more reading and research. My XP has been ridiculously stable - I never have to reboot, I've had like one virus scare on this machine (no IE for me, and no Outlook), and it turned out to be nothing, and that seems to be the most usual argument for a Mac. Even my Service pack 2 problems turned out to be a bad RAM problem. Jury's still out!
Many thanks for everyone who had helpful thoughts to share on my new computer advice request!
Now, I've got a stack of orders to label and more to make!