I've uploaded an animated tutorial to one puzzle. It explains some of the basic techniques on quite a nice puzzle.
It's nearly 2Mb and given that my website is on Geocities, that equates to 2 views an hour So if someone wants to mirror it feel free.
Actually it was 2.7 Mb but geocities was not keen to upload that. So if someone has got some spare bandwith I could email them the original animated gif. The new one rushes through the latter stages of the puzzle, but by then it's all just singles.
anyhoo here's the addy:
http://uk.geocities.com/aidan_001/heart.html
enjoy