I found this out today after installing a directory to replace my links pages. Just getting through the first page of links, I was very suprised at how many site had removed my link, and a good number of them had actually removed their link page now that they had some decent pagerank and traffic. Took forever to get through this manual changeover due to the time spent searching for my link on these pages. I wish I would have went to this directory from the beginning. It sure makes verifying links alot easier.
use a link managing software which is able to run cron job in backend to check backlinks. There are lots of softwares. Because I can't provide live links so PM me if you want to know their names.
Your are permitted to provide live links when providing help, so post away I'd be interested to see what options there are aswell.
I was using nothing. Just adding links manually to an .html page. I set up a directory for my links page now, using phplinkdirectory. It is much easier or me to verify links now, and takes alot of work out of the process of adding links. Here is my new, unfinished directory - http://www.sportsoutlaw.com/links/ Once that is done, I will probably make a duplicate for non sports related links if I decide to include them.