Thanks to all of you for your comments!

I just tried upx3 with --lzma and it was resulting in 50K. UPack gives me 47K. Not much of a difference, but 48K is such a nice limit :-) For the next project upx of course is an option, it's the exe packer I'm using normally, and I like it very much.

This leads me to another question: has anyone here tested what Delphi version is best for small executables? What about FreePascal?