I’ve just installed the websnapr plugin for wordpress, this plugin produces a preview bubble for external links eg. The Register which I quite like, I’ll use it for a while and see how I get on with it hopefully I’m not going to have any problems with it. All you have to do is add
<a href="http://davereid.net/blog" title="Pmetric pluging website">Linktext</a>
To any external html link that you insert, so it’s pretty easy to use.
I’ve just removed the snapr plugin in favor of the Snap Preview AnywhereTM plugin. This one seems to work better. It has the added advantage of you not having to create html code for links, see above.