MathService is a Mac OS X "Service" that utilizes MathLink to perform Mathematica evaluations from any Service-aware Mac OS X application. To install & use:
* download and unzip MathService.service.zip * copy the resulting "MathService.service" icon into ~/Library/Services (you may need to create the "Services" directory) * log out and log back in (this is necessary for new Services to be recognized * open a services aware application (such as TextEdit) * type "2+2" (or any other valid Mathematica syntax) * choose "TextEdit"->"Services"->"MathService"->"Evaluate To Text" from the menubar