Flitz. Available in Tampa at Buzz-Off Alarms and Audio. Located at 7212 N. Dale Mabry (1/2 mile South of Waters) We also have a polishing ball that attaches to your drill.
Flitz or Met-All are both good products- for badly tarnished or dull aluminum that is churning up a lot of black residue as you polish, use flour to remove it. That will speed up the process a lot!
If you want it polished to perfection than try the above. Propblem is keeping that perfect finish can be a *****. If you want it shiny try some fine steel wool and WD40.