I think Longshot would be pretty cool:
Known Superhuman Powers: Longshot was genetically engineered to have certain superhuman abilities. One of these is his ability to affect probability fields through psionic means in order to give himself "good luck" in his activities. This power operates even when Longshot does not consciously will it to do so. However, by creating "good luck" for himself, Longshot creates an equal and opposite effect elsewhere, thus creating "bad luck." This "bad luck" could affect someone else, or could conceivably even affect Longshot himself at some point.
Weapons: Longshot carries a number of cleaver-like blades, which he can hurl with great accuracy.
If Galactus knew this, he would lower the "bad reaction" aspect of Longshot's power, while raising his good luck. THe result: Longshot, sometimes through skill, sometimes through luck, might be able to find planets faster for Galactus.
The cleavers would become cosmic weapons that Longshot could create at will.
Of course Big G would beef up Longshot so he wouldnt look like a wimp anymore. Longshot could make a pretty formidable herald!