CalcService calculates the result of a selected formula within all Cocoa-applications (e.g. Textedit, Mail, Stickies, Notes, ProjectBuilder, Safari etc.) and appends the result to the formula or replaces the formula with the result. In addition there's the possibility to display the result in a panel without modifying the text. So there's no more need to start Calculator or open the Dashboard if you only want to calculate some values immediately within text view or dialog fields.
MEKKA I can't live without this service anymore. It's nearly perfect. Fast, stable, reliable, works anywhere!
The only thing that bugged me the other day was that CalcService doesn't accept an equals sign at the end of the marked calculation when you hit command-"=", I guess it could be more tolerant there.
But hey, I can't complain! It's very precise, blazingly fast, and it's FREE! (Version 3.1)