Fring has a thing for Nokia as of late, it seems. It wasn’t too long ago that they added N810 support; then two days ago, they added support for the Nokia E71. Now they’ve gone and added the Nokia E66 to the list. I’d point out that there are other handsets Fring can be adding support for, but it seems like they’ve already got most of them covered.
If you’re looking for a way to Skype, MSN, ICQ, Google Talk, SIP, Twitter, AIM or Yahoo IM on your E66, head over to Fring’s download page.