Computer help: 2 computers into 1 easy workspace, help me figure this out?

2 computers into 1 easy workspace, help me figure this out?

For the past 2 years my primary computer has been a 15'' G4 powerbook. I'm a college student involved in media arts and we primarily work with mac's, before this I had always used PC's. My roommate is buying a new pc to take place of his current pc and I'm going to take it from him so I can start catching up on all the pc games I've been missing out on the past couple of years. Anyways, I'd like to try to get the two computers running on one monitor so I don't have to set up a 2nd desk in my room. I've been thinking over my options and I want to see if anyone can maybe offer any suggestions to what I've thought of so far.

So here's what I'm working with:
-Monitor-
Dell 1704FPT 15'' flat panel monitor. I just got a really good deal on this monitor this weekend from someone in town, and it appears that it has 2 video inputs VGA, and what ever the name is of the mac video cable. So apparently I can plug one in straight from my mac and use the VGA for the PC. With the touch of a button on the front of the monitor I can switch between these 2 inputs it appears. That takes care of that.

-Audio-
I have a simple speaker setup, 2 speakers and a subwoofer which use 1 1/8'' mini connection. I'm planning on using a Y-Splitter with 2 male ends and 1 female end. I will plug the speakers into the female end and run extensions from the 2 males ends to the pc and powerbook. I don't think the 2 computers sharing the speakers and cables should cause a problem, more than likely I'll only be doing something on one at a time. I figure it'd be possible to probably play from both okay too if I really wanted to. example - perhaps playing music from my itunes on the powerbook while playing a game on the pc?...

-Mouse-
This is where it starts to get tricky. I know of KVM switches, but I'm trying to get around using one of these for whatever reason. I have a USB 5 button microsoft mouse with scroll wheel. I have 2 4-port usb hubs that I could work with. also my monitor has 4 usb ports on it. I figure that it may be possible to plug some peripherals into a hub or directly into the monitor and perhaps switch plugging in cables that go from the pc/mac into the monitor (if that makes any sense). So I could have 2 cables on the side and just unplug the pc and plug in the mac if I wanted to switch between the 2. I figure this would be easy to switch because it's right on the side of the monitor.

-Keyboard-
Even more tricky. I am currently using an Apple wireless keyboard and I would like to continue to use this keyboard if possible. I know it interacts with my mac via bluetooth, but the pc I am getting doesn't currently have bluetooth. I figure I could easily install bluetooth into the pc, but I don't know how easy it would be to switch the keyboard between the pc and mac. Pretty much I think this is where i'm stuck and I don't know how well this would work at the moment. I know I could make it work, but it seems like it would take too much time to switch between the 2 toggling through options on the mac to turn bluetooth off and finding the keyboard on the pc and visa versa.

-Other-
The only other stuff I'm really concerned with switching between the 2 computers at the moment would be 2 external USB 2.0 hard drives that I have. I could easy just have a hub on my desktop that I use to switch from the pc to the mac, so I'm not really worried about this. I'm not really sure if my Harddrives are formatted to work on a pc at the moment though, so that could be a problem, I've just been using them on my mac and I'm not sure if they are formatted to a proprietary format or something.... Be nice if I could get them on the pc though to easily share files.

------
So I believe that is the basics of what I'm working with, I love my mac to death and I still want to use it for all my applications such as web browsing, typing, video editing, photoshop, etc. The PC I'm getting primarily to play games. I want the easiest and fastest way to switch between the 2 devices without suffering performance too much. it appears that a KVM switch may be easier, but I don't know if it'd work well between a mac and a pc with a usb mouse. Plus I have the wireless keyboard and the monitor already has 2 inputs so it'd spare me the change on an extra device. Currently I'm thinking it'd probably make things a lot easier if I ditched the wireless keyboard and possibly found a usb keyboard or something like that.

I think that's a pretty comprehensive look at what I have and what I'm trying to do with it. If anyone has any ideas on how to consolidate this into a more managable task feedback would be greatly appreciated! Thanks ahead of time!