Comments on the last entry raised the possibility of playing a PC sage-with-bodyguard double-act. The sage gets the glory; the bodyguard gets the XP. This keeps sages nicely wimpy (why bother with the frivolities of combat or the hocus pocus party tricks of spellcasting?) while providing an outlet for their XP gains and proper protection for dangerous expeditions. I like the idea.
I wonder if it could be expanded to general play. Every time your character garners enough XP to gain a level you can instead elect to find him a henchman who the XP goes to. Your first level fighter could go up to second level.... or, instead, get a first level thief as a glamorous assistant. The XP left over (because a thief level costs so much less than a fighter one) gets saved towards that nice new first level magic-user you've had your eye on.
The DM might want to restrict the number of henchmen, chiefly at higher levels - big XP rewards could theoretically allow a PC to employ a miniature army of first level thieves. But then again that's not all that different to what happens at name level anyway. There's also a natural break on numbers because XP rewards get diluted the more henchmen there are - if a PC has five henchmen, all getting shares, he garners less XP to spend on his growing throng.