Here I eventually provide the lens profiles for my Sony A900 in combination with various of my lenses. These profiles only work with Lightroom 3 and the latest Camera Raw and eliminate distortion, vignetting and chromatic aberrations.
Here are the download links to the profiles:
A900 + Carl Zeiss AF 24-70mm F2.8 ZA T* SSM: http://www.mediafire.com/?dh4c6kw8r4xvonq
A900 + Sigma AF 12-24mm F4.5-5.6 EX DG Asph: http://www.mediafire.com/?ip3g8dt64et8m63
A900 + Minolta AF 100mm F2.8 Macro: http://www.mediafire.com/?bemre9ue7o5agjb
A900 + Sony AF 50mm F1.4: http://www.mediafire.com/?ndkkri1e1dli7rt
A900 + Sony AF 70-200mm F2.8 G SSM: http://www.mediafire.com/?5z4xhz931pr1l7i
IMPORTANT: It is possible that these profiles will require your lenses to be named correctly in the EXIF data of the respective photo files. I am not sure how tolerant Lightroom 3 is, but if for example your lens is named Zeiss 24-70 instead of the name which I use (Carl Zeiss AF 24-70mm F2.8 ZA T* SSM), my profile might not be recognized. Therefore you might have to change your lens name in the EXIF data. While this sounds like a lot of work, especially if you already have a ton of photos made with this lens, there are actually some convenient free software tools that can help you:
Personally, I use the free AlphalensInfo software, in order to automatically recognize my Sony lenses and to write the correct lens name to my EXIF data. The software takes a little bit to get used to, but in the end it works very well. Download and instructions can be found here: http://www.equational.org/importphotos/alphalensinfo.html