You decide: Stroke of Genius?..or just a Stroke??

2Cable Modems Idea:
I currently have a PC and a cable modem for my broadband internet service with AT&T. I recently got an XBox and the Live service as well... unfortunately, it's set up in a room about 30ft away where I have cable tv.
My situation is this, I'd been deliberating on getting a Wireless router(wife doesn't want 40ft of unsightly cable running through the house) and whatever it would take to connect my XBox to the network.
Then I had this thought: Maybe I can just buy another cable modem, split the signal coming out of the wall, continue running cable to the tv, but the other to the 2nd cable modem (at less than half the cost of doing a wireless setup). Is this feasible, or am I smoking cat hair???
AT&T said I can't, but I don't know if AT&T's just discouraging it so that they can squeeze more $$ from me.
-Thanks in advance for your help.

can't you just run the wires in the wall or the basement or something? Your 2nd cable modem idea won't work unless like the other poster said you pay for a 2nd IP, which would eliminate your cost savings.

<i>It's always the one thing you never suspected.</i>

I tried to install two cable modems in my house when I get a new one to replace the one I rent from cable company. It did not work. You have to disconnect one to use the other.

Thanks for the posts everyone!! I meant to add... My idea entailed that I would just hit the off button on the PC side cable modem when I was about to do the XBox thing...
Would that then solve my problem, since I wouldn't require two IP addresses simultaneously?
While I would still have to run cable in this scenario, it would be about 6 inches and the whole modem could easily sit out of sight. I can get another cable modem for $70(rebates involved). I haven't been able to come close to that with a wireless router and bridge combo...