IDA Pro
I recently discovered a really cool tool called IDA Pro. It’s an interactive disassembler with some powerful features that make examining low-level code and debugging very easy.
I’m currently working on getting IDA Pro to talk to my Lauterbach JTAG Debugger via GDB Remote Serial Protocol, but it seems that there is a bug in the Lauterbach software. The two products should make a very powerful combination.
Check out IDA Pro at http://www.hex-rays.com/idapro/