This is how you use those photon drops you have found.

To use the drop, you must do the online quest 'Gallons Shop.'

1. Head down the ramp in Pioneer 2 to the open space. You know, the place where you telepipe to when you telepipe out of one of the areas in Episode 2.

2. Now, once you are here, you need to find the guy in the corner, in the the little nook next to the ramp.

3. Talk to him, and he will exchange your drop for certain items.

3a. You can exchange more than one drop at a time.

3b. There are certain plateaus that you trigger with certain numbers of drops. Think of them as prize levels. The first level is from 1 to 16 drops. Once you get to 17 drops, the prizes get slightly better. There are additional, higher levels, but I haven't seen any definitive information on them.

3c. Common sense would tell you that unless you have 17 drops, you might as well just trade them one at a time. Why trade 3 drops when you get the same prizes as 1 drop?

Ok, I hope that answers your questions. If you have tried all this, and you still can't figure out how to make it work, then ask.