I've been reading through and catching up on my Windows Secrets Newsletter and found the article on using services like LongURL to expand suspicious URLs. I realized an easier way that wasn't mentioned. Rather than using a plugin to expand the URL directly you can do a search for the URL in your browsers built in search engine. In Opera you already have the ability to this, in Firefox you can get an addon called "Add to Search Bar". Once you have the ability simply go to a site like LongURL right click in the URL paste bar and click add to search bar. Follow the onscreen instructions and you'll find yourself with a new 'search engine' that can expand your links without a popup. Additionally in Firefox I use the addon tabmixplus which can automatically open searches in a new tab bar. So by combining these you can open the LongURL (or whatever service you want) info page in a new tab with very little effort.

This by the way is exactly how I have my main browser set up since I don't want to be adding and keeping up on an addon (I've got enough and I don't have to worry much about my search engine becoming out of date).