Micro Miners (iPhone iPod)
CheatingDome.com
Various General Tips
Tip 1: Don't mix up miners of different colour - you'll end up killing half of them when you go for a deposit.
Tip 2: Build walls in caverns before you drop your miners in, otherwise carnage will ensue.
Tip 3: Your miners can hop, so zig zag your tunnels if you want to send them upwards.