Gotta agree with both people here. Obviously, you should have checked to ensure that the TV had the adequate inputs/outputs for your equipment. Most TVs these days have far more than one HDMI input, so that really is a big suprise that it ONLY has one input.
The component input, which likely is shared as a composite video input, is also typical as 99% of all new equipment has HDMI on it.
My brand new 64" Samsung plasma? 5 HDMI inputs, 1 shared component/composite input.
What do I do?
ANSWER: If you don't want an A/V receiver with upconversion, then just get gear which sports HDMI output on everything!
The Wii has a component cable which you should be using anyway for best video quality.
Magnavox has a combination Blu-ray/DVD/VHS player which has HDMI output and will allow you to play back Blu-ray (HD!!!) discs while giving you the backwards capability of playing back VHS tapes using a HDMI output.
Then your cable box and any other modern game system will have HDMI output.
There certainly are some cheap component video switchers available though, and realistically, that's all you should need.
In the future... when asking for help, feel free to provide actual model numbers of all your gear.
IE: "I just bought a Vizio 46DNLPOS and I have a XBox 360, PS3, Wii, Cable Box (HD DVR), and a old DVD/VCR (Philips JNK1) that I need to connect."
This will help us perhaps give you some better answers to things.
On a shared component/composite input, you can still use a basic component video switcher, but land the video on the input designated for composite video.
S-Video is dead, don't bother thinking about it.
Something like this will work, and likely will sell for under $20...
http://www.ebay.com/itm/Phillips-AV-Switch-Component-Composite-S-Video-/200648881149?pt=LH_DefaultDomain_0&hash=item2eb79af3fd