I love this style of table. Naturally, the French deserve credit for this beauty. Louis XIV populated Versailles with them. They can be at home, however, in much more modern applications.
Additionally, to me, they are a great piece to have around. It's small, so you can always find a home for it. And while you wouldn't want to permanently store one of these beauties outdoors, it could certainly serve outside admirably.
The tabletop is usually circular, but other shapes are out there (see above). I don't think the X- supports are necessary for the table to be a Gueridon, but the style is typical of the most well-known tables. Look for pairs like the ones above. They are also most often created in brass or bronze, but I could imagine a more modern interpretation in brushed nickle. I'm sure Pottery Barn had a knock-off Gueridon a few years ago, but I can't find a photo. It must be off of their web site.