[throwanem]

28 bytes out of ~225 bits, sure. (I compute 228 bits, but precision gets funny with quantities so large. Interestingly, an emulated TI-86 and a real TI-89 Titanium returned different answers; the latter wasn't even divisible by 8!)

For movie-plot '52 pick-up' that's not so bad, especially if used to encode something like a key for the "Solitaire" cryptosystem, mentioned nearby, wherein the same deck can in turn be reconfigured and manipulated to generate an arbitrary-length keystream for application to a longer message transmitted under separate cover.