Variegated Meadowhawk (Sympetrum corruptum), Newport, Oregon, USA
This appears to be a male, just beginning to get its adult base coloration (red)
There are 18 species of Sympetrum dragonflies known to occur in North America, plus a number of other small, red or yellowish dragonflies that might be mistaken for a Variegated Meadowhawk on cursory inspection. Thus, it is important to try and get a good look at the dragonfly through close-focusing binoculars or by catching it and inspecting it in hand. Look for this combination of characteristics to confirm your identification:
Thorax ("chest") with 2 white stripes on each side subtended by a yellow dot (in older males, the stripes may fade, leaving only the yellow dots); a row of pale spots along each side of the abdomen ("tail"); veins along the leading edge of each wing orange-red; eyes red with gray highlights; legs black but yellow on the outer surfaces.
In my experience, Variegated Meadowhawks are much more skittish than the other related species that occur in my area. They are prone to flush (in the sense "to fly out or start up suddenly") when you are further away from them than the other species, and tend to fly a greater distance before alighting once disturbed. I don't know whether this holds true in other localities with different sets of species. By itself, it isn't sufficient to nail down an identification.
If you look at the above picture closely, you will notice the variety of colors in the dragonfly: red, yellow, gray, white, and black. This variety of colors gives it an overall pale appearance compared to similar species when you see it out of the corner of your eye as it flushes from cover. Again, this should not be considered definitive, but can at least suggest that you have seen this species.
Variegated Meadowhawks often perch on the tips of bushes and similar vegetation, warming up in the afternoon sun. When they do, the orange-red veins on the leading edges of their wings reflect the sunlight, and they glow like rubies. This is a most attractive species!
If you are interested in observing dragonflies in North America, you would do well to purchase the book Dragonflies through Binoculars: a field guide to Dragonflies of North America, by Sidney W. Dunkle (ISBN 0195112687). It can be ordered from the International Odonata Research Institute (http://www.afn.org/~iori/), which is also a good place to start looking for information on dragonflies.