White posted this URL on his blog, it looks interesting to look into.
Are there people who have experience with Pure Data (PD) ?

http://createdigitalmotion.com/2007/01/18/open-source-motion-tracking-with-multiblob-for-gridflowpd/

I am curently working on a set of externals using opencv blobslib for Pure data.  I found blobslib before finding touchlib so I had alot of time invested to change.  I think with blobslib you can have a higher number of blobs (i heard people working on 100-200 blob projects) with less of a cpu hit because of the algorithm used.  Anyway if people are interested and are willing to give comments and advise, I will post it when I’m done.
Alain