Evening all,
I was just helping on another thread and was looking for a freeware program that I could recommend him downloading, in order to validate his web page.
I came across this one...
http://www.htmlhelp.com/tools/validator/
...that doesn't require any downloading. If you're already up and running, you just enter the URL and wait a minute or so for the results, or you can upload a "work in progress" and it will do the same.
I just ran one of my sites through it; built (or in the process of being built, anyway)

on a freeservers template, and it found a raft of little errors.
Any experts around, or anyone else for that matter, that want to check it out and confirm it's err... validity
Cheers
Liam