Right. So I got this idea. My current setup is I have my laptop directly infront of me on a small stand. I use it most of the time for gaming and general use.

My TV is on the other side of the room, with my PS3 connected to it (via HDMI).

My vision isn't really good, so when I go to play a game on my PS3, seeing finer details (such as the sniper in the bush 200 yards away) is HARD.

So my first idea was to set it up so that instead of my PS3's display going to my TV, it going to my laptop (which has an HDMI port), since the screen is right in front of me anyway. However; I still want to be able to alt-tab back to my desktop freely because I want to be able to change my music and what not while I'm playing.

My second idea, to try to help against the switching music and what not is to then put my laptops display on my TV. Now, I know that should be possible, however; I only have one HDMI port on my laptop. So I don't know how I could set up both of these things.

That being said, is it possible to stream my PS3 gameplay to my laptop via HDMI while still being able to access my OS so I can change playlists in iTunes and message people on skype? If so, do you have a BASIC tutorial on how to do it?

Simple answer is no.
But they do make mufti media  swish devices for about $300. That may be more than what you want to pay.HDMI port on your laptop is output only so you can't use it as an input.  There is a WAY to do what you want using a device called an Easy Cap: http://www.amazon.com/gp/product/B0019SSSMY/ref=pd_lpo_sbs_dp_ss_1?pf_rd_p=1944687602&pf_rd_s=lpo-top-stripe-1&pf_rd_t=201&pf_rd_i=B002H3BSCM&pf_rd_m=ATVPDKIKX0DER&pf_rd_r=076Z0PBFA2GHHJ7WMP10.  It's a video capture device that you can use to capture the output of the PS3 and bring into your laptop via the USB port.

Here's a YouTube video that shows how to do it: https://www.youtube.com/watch?v=tr9XGvldziUUnfortunately EasyCap won't ALLOW me to stream it HD to my laptop. Was the plan, to get image quality like my TV but closer.

Yeah, $300 is a bit too much. If I'm gonna spend that much I should just spend it on the new glasses and HOPEFULLY see the TV better xD