I'm guessing that "the tip" is your version of a dump or landfill. If it's not good enough to give away then that sounds like your best option. At least you can recycle some of it, so that's good. I thought of another option for getting rid of a bed that is still good enough for someone else to use: Freecycle. Even if you can't actually sell it, you might be able to trade it for something good, or just get to know people who exchange things, which could come in handy later. Depending on your area, there may be a local Freecycle group online.
Update: A friend just tried to give a bed to a charity organization. They were really picky about it; it has to be in a certain condition, can't have stains... he put it on craig's list for curbside pick up and it went the same day! He got rid of a couch that way also.
If the bed is indeed in very poor condition, then you can have a local organization haul it away. This includes non-profits or a simple junk hauling service. Otherwise, you can take it to your local landfill or cut it up and burn the wood within the mattress.
If it still has some life left in it, you can call the Salvation Army and ask them to pick it up. In my area they have a truck that picks up donations of items such as furniture and appliances. They have a regular schedule, so you'll have to make arrangements on your end to be home when they can get to you since they don't have the means to be all that flexible. If it really is trash, you'll have to rent or borrow a trailer and take it to the dump since there really is nothing else you can do with a mattress once it is worn out.
