I'm looking for a way of concealing the text strings in an object file so that they can't be seen. I'd like to use something a little more complicated than rot13 :-), but something that's freely usable for non-profit use.

I assume you mean so that running "strings" on the binary will not lead you to anything, right? You can use an XOR with some weird value to hide the strings. Just make sure the value you use will, for example, set the high bit on the string bytes... Its is a cheap, free way to hide strings. It is, by no means, secure. -derek