Converting bottle-neck code in C
Finally gaining the really needed (much more) speed converting the bottle-neck code (the image conversion functions module) in C, as compiled extension instead of pure python module.
Some initial benchmarks (iPod video 5G on a Centrino 1,7Ghz with 1Gb of RAM) are telling that image uploading to iPod is from 2x to 4x faster than before, taking approximately 1 second long per image, almost the same of iTunes. 
To achieve the best speed, you could choose stretch as image uploading behaviour, autorotation disabled, w/o full resolution image. Of course using Nano iPods the process is always much faster than other iPods, because they use only 2 kinds of thumbnails, instead of the usual 4 types used in Photo/Color/Video iPods.
The new C code is currently in pre-alpha testing phase, and it will be the major feature of the upcoming 0.6 release. Currently, a working version is already in SVN: if you want to try it, check it out and report your feedback! 