Lots of things! My pallet forks are the one attachment I've bought where I can directly say, "This saved me money". Number 1 money saving use of my pallet forks? Avoiding lift gate charges for equipment deliveries. Just stick the pallet, and then I can take my time to put the machine (woodworking machines usually) exactly where I want. Given that lift gates are often 100+ on a single delivery, doesn't take many before you break even/"make money".
I also use them all the time for moving wood in IBC cages. I'll take the cages out where ever I'm splitting, chuck the wood in there, put the cages somewhere to season, then go get them when it's cold and move them right next to my back door. I never carry wood except from the cage into the house. But that's one carry compared to the 3-4 I used to do before I went to to the cage/pallet fork system. Love it!
Sometimes I use them when I'm cutting wood, get under the wood with the forks and lift up to make it easier to cut/not cut dirt.
I have a big spade that goes on the forks, I use that sometimes to dig if my backhoe isn't available.
I built a box, about 4x4x3 that I use when I'm chipping, it's a pallet underneath and I'll take the box, fill it with the
chipper, and then pick the box up and take the chips where I need them. That works very nicely.
I'm sure I'm missing things. Oh, yeah, unloading bulk material in 1,000 or 2,000 lb bags (sand/crush and run/etc). Slide the forks through the handles, lift up, take it where it needs to be, cut the bag.
Man, this is making me sound lazy! But those pallet forks are my number 1 SSQA tool. I have a bucket, a bucket with teeth, a grapple and the pallet forks. Pallet forks were the cheapest of all of them, and probably get more than 50% of the overall use of the SSQA. Love them! Got mine from EA, it's a very simple device, so I'm sure they are all pretty good, but I'm very, very happy with mine. Love to have a hydro adjust for the forks, but that's just getting too lazy even for me!