Saw this for Mac at [link]
and wondered how easy it would be with Mint Linux. Turns out very easy if you know what you're doing, although it took me a week to figure out what I was doing.
This was my first venture into Conky (and Lua), but I'll definitely be doing more.
If you want to do this yourself (Linux only), just click 'download' and follow the readme. Sorry it's a .zip file; apparently DA doesn't like tarballs.