>your best bet is going to be to get something that encrypts and compresses the .exe - that way the only way someone can get to your source would be to load the program into memory then do a memory dump and decompile from there. still going to be possible, but will require the cracker to have more tools and more time.

Or an UDF based index on some table which dumps memory or files with filetostr(). Then is easy with Refox.