I accentally cracked teh lcd of my SD400, is there a hope that it could be fixed at all, or I just have to get a new one?

If it was a totally out-of-the-blue crack (like while it was in your pocket or something), there'd be a chance of getting it replaced without cost, since you could argue it was defective. But that is really difficult to do since nine times out of ten they will call is mishandling, and since you said you accidentally cracked it, I'm assuming it was a case of dropping it or something similar.

An LCD replacement is not covered by warranty due to the high cost of repair, or so I've been told. Getting it done by a repair shop will likely cost you more than a new camera. So your best bet may be to replace it.

With all that said, there was an issue awhile back where the company acknowledged a design flaw in some of these little SD cameras, because the LCDs did break very easily. So if I were you, I would call Canon and talk to them. A person on this thread says that they spoke to Canon customer service, and got a "courtesy repair" done for free, just one time. Perhaps worth a shot.