Screensavers on S60 3rd Edition 
Many asked for a product like "S60 Screensaver Maker" for 3rd Edition phones.
This is possible in theory but the generated SIS needs to be signed. (look
here for a complete example). That makes the whole idea impractical.
The good thing is: On 3rd Edition FP1 you won't need it anymore since it directly supports SVG, SWF(!) and GIF(?) as screensavers.
I wish they had added support for these kind of screensavers sooner.