Mac won't boot and some other stuff

Hello, (first post here)
I was using my iMac last night to watch a dvd, and I forgot to eject the disk before I shut the computer down. This morning I tried to start it up and the computer beeped first twice and then kept beeping three times, and this gray screen appeared. I tried to eject the disk, I tried holding the option key but none of that worked.
Could anyone help me a little?

Ejecting the Disk is holding down the Mouse Button. Hopefully the beeping was a result of you holding down the wrong key, otherwise it means you have a hardware problem.

The beeping didn't happen only when I pressed any keys, it started as soon as I tried to start the computer. I tried holding the mouse button down and nothing happened. Maybe I'm doing it wrong, for how long and when should I press the mouse button (and also, is it just the left one)?
Are there any other ways of solving this problem without having to take it to apple? There are no apple stores in my country, and the nearest support center is in a city which I have to take a 2h flight to get to.

I'm sorry there is no Apple Service Provider closer, it could be worth another check. It doesn't have to be Apple Inc.

What sort of Mac is it and what OS are you running???

Beeping Tones normally mean a Hardware Failure, there is very little we can do.

It could be the struck disk, but to get that out if it won't self eject, is to take the drive out and pull it apart, so it's not normally something to try yourself.

If it's a SIMM problem you might be able to swap out the faulty card with a replacement, this is fraught with static problems. (We no longer provide warranty for user installed RAM, and install them for free, the problem is so bad).

TONES ERROR
Error Tone. (two sets of different tones) Problem with logic board or SCSI bus.
Startup tone, drive spins, no video Problem with video controller.
Powers on, no tone. Logic board problem.
High Tone, four higher tones. Problem with SIMM.

Thank you, kaveman! Although I didn't succeed in getting the dvd out, the information about the tones was really useful! I'm using a late 08 20' iMac with snow leopard.