Flaked rice is an adjunct that can add more fermentable sugar to the beer, without adding much body or flavor. Basically it's a source of more starch for the malt enzymes to turn into sugar. Some megabreweries (such as Coor's, I think) use rice in their light lagers to lighten the body while still maintaining alcohol levels (though they convert it to sugar beforehand, rather than adding it to the mash).
So yes, you can use it. Homebrewers tend to stay away from it because of its association with cheap light lagers, but there's no reason it couldn't be used well. Some craft breweries use flavorful rice in their beers to give it a unique flavor; Great Divide and Kiuichi, for instance, each have a 'rice ale' that includes some rice in the mash.
If you use it, just make sure you have enough enzymes in the mash to convert it; it doesn't have any itself. Also, I've heard it recommended that you use somewhat lower temperatures, though I'm not sure why. Might just be because if you use rice you probably are looking for greater fermentability.
If used in a strongly-flavored beer, it likely won't add any discernible flavor. In more delicately flavored beers, you may taste a touch of rice.