I wanted to provide a quick update, and thank everyone for their help.
I bought a used hard drive for about $26 at a local university surplus facility, slapped it in there, and (with considerable trepidation) installed Ubuntu. Never even used it before, so I wasn't sure how it would go.
It installed flawlessly, and within 15 minutes of dinking around, I got the wireless to work. So, I have a computer that does everything I used it for previously (surfing the web, doing email, using OpenOffice), and I'm looking forward to exploring Ubuntu more.
The old hard drive is probably toast, but it's not so big a problem as one might think because I've always treated this laptop as a junker- keeping nothing of value on it in case it got stolen or DIAF'd.
Thanks to everyone for their insights- I appreciate it!