Unique image hash

[TheVig]

I'm thinking I'll use DateTime + the first 4 characters from str HASH.encrypt(2|8 sPath "" 0x100) to return things like:

130210821264631349_543A.jpg
130210821265881565_655D.jpg
130210821267131781_0EFF.jpg

That's about as long as I want files names to be.
I also want to be able to sort by the original date created...so having that information in the filename is important.

Better ideas?
jim