I think the 10-shot speedloader (the DS-10-SPEED) is about the best thing since sliced bread...though I think it's the $5 loading block that really shines: I can load 40 shots on that block, and since the speedloader is loaded just by pressing the body of the loader onto the rounds, reloading the speedloader is quick and easy, and faster than loading the HKS speedloaders. One DS-10-SPEED and a loading block is something like $35.
Of course, if the game you're interested in requires you to have the speedloaders on a belt, then the loading block won't work out so well...but I don't find that to be much different (or less expensive!) than having a couple magazines in your pockets, either.
You could do that, too--single load the .22 rounds from, say, a Ruger Mk. II/III magazine, and use the Ultimate Clip Loader to load the magazines really quickly. I've done it in Bullseye competition, and with practice it isn't too much slower than using the DS-10-SPEED loader.
Either way is much faster than single-loading by hand, though.