Recently, Matt Cutts on his blog suggested a way of getting free links on your site quickly and easily, using Google's Webmaster Tools.
Google's Webmaster Tools contains links to pages that people have pointed to, but they're not on the server (404 errors). So say if somebody created a page to deadsite.co.uk/itisnothere.htm, and you either removed that page (or, more likely, they mistyped the URL), so how do you create them into good links?
Way 1 (Poorest) - Meta Refresh
The first way is to use a HTML meta refresh such as this:-
<meta http-equiv="refresh" content="0;url=http://www.target.url/"/>
Put that line of code inbetween the <head> tags, and save it the name of the link that is mistyped. This is one way to do it, but it isn't the best. For one there's no search engine benefit, and secondly it can be misleading at times, especially if the user pays particular attention to the address bar. They'd think they'd gone to the wrong page!
Way 2 (Better) - PHP Redirect
A better way is to do a PHP redirect, using similar code to this:-
<?php header("HTTP/1.1 301 Moved Permanently"); header( 'Location: http://www.target.url/' ) ; ?>
This works, as it tells the search engine that the page it was linking to isn't there, and it passes on search engine ranking. However, it can confuse users at times.
Way 3 (Best) - Informational Page
The best way however is to create an informational page. This can either be done manually for all the dead links you have, or you can create a fancy script (or find one!) that informs the user of their mistake, and what they can do instead (as well as push more posts, maybe a bit of adsense too!).
What this does is that it creates a little bit of Search engine benefit, but more importantly informs the user of their mistake. In an ideal world, the user who clicked on the link either manages the website, or writes to the manager informing of their mistake. Either way, it helps build trust in the users.
So, instead of blindly chasing links, why not check out the ones you've already got?