Scotts All in One Tool Kit
This gives you just about everything you need to remove most of the small fasteners on your bike. It uses standard 1/4"-drive sockets so you can add additional sockets to your bag to cover any extra sizes. I also carry a six-inch long 1/4" hex extension with a magnetic tip to get a little extra reach when needed. The ratchet with Phillips tip is just about the best tool I've found for removing the float bowl. The only problem with this kit is that the pieces regularly fall out of the carrier, leaving them hard to find. Keeping the plastic bag the kit comes in helps with this.