gpSP is a well known Gameboy Advance emulator available for a bunch of systems. It was initially written by Exophase.

Changes:

Support for Symbian^3
Better Audio
alpha channel for keys is now configured at video section (not in controls panel)
8-directional / 4 directional DPAD
Hidden A+B button areas
save/load states is now working

http://www.summeli.fi/?p=2520