Harron_k._appl 2010-07-04 17:44:33
It is unclear which version of Illustrator you are using, but here is some additional information.
1. While the pen tool is active, the Ctrl (not Alt) key will get you the last used selection tool.
2. In AI 12 (CS2), to switch selection tools via the keyboard while the pen tool is active, hold Ctrl+Alt then hit Tab to toggle. This will actually toggle between your current selection tool and the group selection tool, but once you release Alt, you will have the “other” selection tool (normal or direct).
In AI 10, the Alt key thing is unnecessary (that is, Ctrl+Tab will toggle the selection tool while the pen tool is active).