If you're looking to jump on the crushed ice bandwagon, and I highly suggest you do, there are a multitude of methods and machines by which you can make your perfect pellet ice. One very simple way is to stop by your local Sonic Drive-In, which offers bags of their famed pellet ice for just $1. Much cheaper than just about any machinery, but there may not be one in your area, or the time inconvenience and counting the price of gas puts cost into more consideration.
For those big time party hosts, or tiki bar professionals, there's no better machine for my money than the Clawson Hail Queen. On the outside, it looks like a square box, and on the inside, a big scary spiked steel cylinder, a motor, and a belt. Simple, but very effective. This burly beast of whirling metal can process a full bucket of ice in just under a minute. Retail, they can run $1800-$2500. But, you can occasionally find a screaming deal on eBay, with hefty shipping, but still a lot cheaper than retail!
Follow this link for eBay listings for the Hail Queen, and good luck!
Of course, if you're just serving for one or two guests at a time, or for personal use, there's nothing like the charm of a vintage ice crusher. Check your grandparents' closet, but more than likely you'll have to look online to find a real vintage ice crusher. In this humble barman's opinion, get real vintage. New manufacturing just isn't the same. My personal favorite is the Rival Ice-O-Mat Vogue edition 455, which has 3 settings for the grade of ice you'd like and can really help take out some aggression with the strength it takes to grind. Find your own Ice-O-Mat on eBay!
There's another method of crushing ice, which involves a large mallet and Lewis bag, putting your ice in the bag and whacking it with the mallet. While very fun, the loud smashing of hammer on bartop can be a bit... perturbing to the atmosphere and is generally not recommended.
Or, if you're just into getting your ice ASAP, with all the modern trappings of custom settings and electronical devices, there's a machine that's been highly recommended, though I haven't had the chance to use one. The Opal Nugget Ice Maker. I've used other "pro quality" machines in the past (hint, unless you paid several hundred and bought it from a restaurant supply store, it probably ain't commercial quality) but was disappointed, but I've heard rave reviews for this. Have your own experience with this or another favorite machine? Leave a comment below!