A new version of GAMESS was released recently. Among the many new features is +Casper Steinmann's recent work on interfacing the PCM solvation method with the semiempirical methods AM1 and PM3. So you can now simulate molecules in solution with AM1 and PM3.
Casper also parallelized AM1 and PM3 (both in gas phase and solution), though molecules have to be pretty big before you see an appreciable speed up, as you can see from the figure below (on small proteins).
The work has been published in the open access journal PLoS ONE. +Jimmy Charnley Kromann is hard at work on implementing PM6.