Your PS3 is fine, if you had a blinking yellow light your need to worry. Just hold the power button down for ten seconds or so when you start it up. That will reset it to factory settings. IF this does not work check your cables and try again. Sometimes it is a bit touchy, but after a few attempts it will kick to a reset screen. This ahppens to me like once a week when I boot from linux back to the PS3 OS.
I can't do what you're saying:
I pulled out the cables and left em out while back at work after my lunch and so I've now plugged them all back in and the PS3 has just a red solid light. When I hold the power thingy (put my fingers over the contacts or whatever) it still acts as if I just tapped it--I get the power on beep, the green light goes on, then flashes yellowish once, then the 3 consecutive beeps and the flashing red light. I didn't really notice the yellowish flash once before the flashing red...does this mean anything different?
If I hold the power button the whole time there is no difference. If I hold the power button down while it's flashing red it only reverts to a solid red (off). Rinse and repeat. Guess it's pooched.
BTW did this happen because I played it while it was 88-90 deg in my house? I did play for like 4 hours or so (MGS4 is addicting).. I was a little wary of playing it while it was so hot but it never acted funny at all so I just kept playing. System worked fine on Sunday and Monday though.