I just wanted to share some wonderful information for those Aperture users out there with a fisheye lens. Image Trends makes a plug-in for Photoshop which is now available for Aperture that turns your Fisheye shots into rectilinear, and it only costs $30. It's called Hemi-Fisheye
I just bought it and installed it about a week ago and am very impressed. Looking at these two photos you can see how well it really works (didn't crop my camera bag in the bottom so you can see the whole effect).
Just wanted to share because i am so pleased with the results. BTW it also works really well with people in the shot.