I recently came across these:

Listed as "Unicorn Horn"...mmm...yes, but you know what you could also use that for...a mini rock drill!

Like with one of these chainsaw holders:

Nifty! I think there was one aqua raiders type set last year where they did something kinda similar.
Another idea I like to use on my space ships is to use these flags:

Along with these pieces:

Which you can then use to create circuitry cover plates like nyah:

There's also a lot of really great non-traditional Lego pieces, from Scala, Belville and that new Friends series that work great for regular Legos.
Like these Scala/Belville baby bottles:

Which can be used as water bottles for regular minifigures.
And the new Friends series, which are very closely comparable size wise to regular minifigures have a TON of really awesome parts that work both ways:
http://www.facebook.com/media/set/?set= ... e8b59848f6I think my favorite is the medical stuffs:
