Do you hate having 30 tabs open in firefox/chrome/whatever when 7 or 8 of those you would really wish they were an application?
I met Fluid this weekend. Mac OS only unfortunately. It made my day.
One of the things I wished for was Google Reader as an application, and now I do. Did you mention Facebook? That also works. I guess Playboy would work too.
Try it and you might find yourself a fan.
There is plenty more you can do with it. Get your imagination working.