I am now a supporter of the crowd-funded open-source project known as File2part.  File2Part provides slicing and file fixing software compatible with a range of 3D printers including MakerBot and Bits from Bytes.  The software provides an easy OneClick solution for 3D printing and supports importing of STL, PLY, VRML, 3DS, DXF, OBJ, LWO and SketchUp Collada files.  Each file is automatically checked for printability and repaired if necessary.  Parts are automatically positioned in the build box and all the user needs to do is press a build button.

Pledge $99 and you will receive lifetime upgrades.  Versions will be available for Windows and Mac with Linux to follow in future upgrades.  More information can be found on their website here.