Hi if you use mozilla then i would suggest to add a toolbar called swoosty - its a great tool and will highlight nofollow links - many more seo tools are included -I cant live without it personally
If you use Firefox (which all IM should be using just because of the plugins available) has a great plugin called NoDoFollow which does exactly that display what links on a website are Do and which are No Follow. Just do a search for NoDoFollow for Firefox and it will come up. This tool is one I always use!
Thank you dear abs007 i add now swoosty toolbar Just a simple extension to highlight links in a page according to nofollow / dofollow status
What i uses-Just go on view source of the page and search for "no follow" or "nofollow" keyword.If you find it then that site is no follow else dofollow.So simple.Not requiring any tool.