Before I go into switches, keep this in mind: with an SDTV, you are sending 480i resolution over Component video--the same resolution that is carried over S-Video cables and composite video cables.
YPbPr Component Video, commonly now known as just "Component Video", came into popularity with DVD players, because a newer signal standard was needed to handle 480p, and RGB (which is technically also a "component" signal) was no longer practical. So before YPbPr become widespread, the best way to send 480i was over RGB, then S-Video. Component video support jumped in right at the end of SDTV's lifespan.
What does this mean to you? It means 480i over component is a poorly-supported standard. I still have some SDTVs... a larger 36", and a smaller 27". When the component input is bad, the result is always the same--a very dim picture, one that requires a complete recalibration of the TV settings, only to end up with a signal no better than the S-Video. That's how it is on my 27" TV. On the 36", the component is brighter, and better than the S-Video, but not by a large margin.
Because of this stupid inconsistency, and the fact that 480i YPbPr wasn't around very long, S-Video is my preferred way to connect to a SDTV.
So if your TV is smaller, or if it has two S-Video inputs, tracking down PS3 and 360 S-Video cables instead might be a better idea... and it may end up cheaper than a switch, if you go hunting on eBay. PS2 cables will work on the PS3, and ones by Monster are reliable and fairly cheap on eBay. But for 360, the only decent cables are made by Microsoft.
But if you still wish to go for the component switchbox, I'd be happy to help with that too. It may be the better option, since you certainly aren't going to use S-Video if you get an HDTV someday.
The monoprice switch will be absolutely fine for carrying 480i component signals, since a 480i signal isn't a lot of data. But if you go into the realm of HD gaming someday, it wouldn't be as good a choice.
This one is a little bit better than the monoprice, from what I've seen:
http://www.amazon.com/JVC-JX-66-Component-Video-Switcher/dp/B0002SPKSM/
I've also seen this locally, so you might be able to get it in a store for a similar price. But you'll have to press buttons to switch between signals. The next step up is this:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=330279535889
These show up from time to time on eBay... usually costs around $30 to $50, depending on who's biting. Auto-sensing, pretty high quality... not highest, around "prosumer" level. I've used one, happy with it. Anything beyond this is very, very expensive.
I hope some of this helps. I know the feeling of being lost in a sea of video connections when trying to hook up consoles, trying to find the right cabling, switches...