Whit Athey has written a nifty Y-haplogroup predictor. You enter your STR data, and the predictor gives you a score for various (mostly Caucasoid) haplogroups. This will be useful to any people looking to get a quick estimate of their probable haplogroup without having to dive into the technical literature for information. Alternatively, GeoGene and Trace Genetics offer haplogroup determination tests, and other labs let you test for particular SNPs after you get a regular STR test.
At least in my case, the Y haplogroup predictor seemed to work fine, even when I entered a small number of values.