The skinny on compression gear

There’s compression gear and there’s tight fitting clothing. One is proven to work through medical design and testing. The other may work minimally or not at all. By “work” I mean promote circulation back to the heart to reduce lactic buildup and post event soreness (DOMS—Delayed Onset Muscle Soreness) and promote recovery. Tight clothing can restrict blood flow and thus oxygen to the muscles needed for work or limit the lactic recycling out of the muscles for recovery.
First, don't waste money on non medical grade compression gear. Get the good stuff. By that I mean the medically designed gear with specific zones or areas for increased and decreased compression based on your body’s muscle groups and their locations in your body. For the calves, it is preferable to go with full socks or the blood can pool in your feet unless you're actively running. As for tights vs socks, tights are better for full recovery, but can get hot in the summer and after racing causing your body to have to work to reduce the heat, so they can be doing negative work at the same time. The best option is to get both socks and tights and use them based on a variety of factors. The Zoot CompressRX line is medically designed compression gear. Most others are just tight clothing that restrict circulation rather than promote it.
The other reason Zoot gear is superior is that it is designed with circumference based sizing. Most other gear is small, medium, large—not as specific for fitting. Be very specific with sizing. Getting the right size is as important as the gear itself.
If you only get one thing, get Zoot socks. If you have the ability to spend some coin, get a set of the Zoot Recovery tights and a set of the socks--tights for right after races and while traveling, socks while in school and walking around. You’ll also want a Recovery top for traveling and post-race on cooler days. Compression gear while actively training is second in effectiveness than for recovery. If you can swing it, get some active recovery gear. If you can only afford one set, get some designed for recovery.
You can get the entire line of Zoot compression gear at Trisports.com (and use code GEC-S for 10% off).

Brian