I found the "astrophotography" here: www.lomography.com/magazine/tipster/2011/11/08/astrophotogr…
Got some nice results with this kind of double exposures :-)
(I've tried other computer screen pictures before, too. But they doesn't really work well. Probably too bright.)
jackpumpkinhead, saraess, lomalex, zgregs, anpank, rotezora & dobendan.
these are all so stunning i love them!