Is it possible to selectively compress files?

Here's the deal, I have a lot of targets to build. Many of which have jpg, png, mp3, etc... which is an already highly compressed state, and only gains a few k per megabyte, when compressed with the LZMA compressor.

What I am wondering is there a way I can turn off the compression for particular files, and back on for others?

As long as you're not using solid compression, you can selectively turn off compression using SetCompress.