How can I repair small holes in vinyl siding?

If your vinyl siding has a color to it, there are one part polyurethane caulks available like Sikaflex that can be ordered online that should match your color, at least a close match so it does not stick out too bad. If the siding is white, well, that is available right off the shelf. Clean up is with mineral spirits and it will last a real long time. It does not have to be Sikaflex either, there are other brands of one part urethane caulk out there too.