I used to do that ALL the time because thats the way Yahoo does it and the only way I figured out how to create a single border in a table... But then came CSS... Here we go, the simple down and dirty in-line style :
<table border="0" align="center" style="border-width: 1; border-color: #990000; border-style: solid">
<tr><td>
Stuff
</td></tr>
</table>
You can replace the style with : dotted, dashed, ridged, inset, outset, double - and a few more i cant remember off the top of my head... makes for some really cool table borders
And as far as I know its compatible all the way back to IE4, but i still use the table inside a table to create my 1 pixel borders - dont ask me why - for some reason i just feel its more compatible.
Also there are GREAT tutorials at webmonkey.com