A friend of mine gave me a Ti frame. there is one crack on the chain stay. Talking with a couple Bike mechanics, half say it's repairable, the other half say to move on.
Is this worth fixing? any idea on who could do it?

your attachment is never going to work for anyone but you because it's in your gmail account. You need to post it somewhere like picassa or photobucket

I'm a jackass

That's the seat stay? Looks like the chainstay at the BB. Anything can be rewelded or splinted and rewelded. If it is the seat stay, then it should be OK because it is under compression. A Chainstay would possibly require some patching as well. Could get tight depending on what else is happening in that space. Other options are tube replacements. I don't know what people charge for that, but it is non-trivial, and I would have thought unless the frame is exceptional it would not be worth it.

Ti welding is a specialty, so you need to find someone who would be able to do it on bike tubes, won't be against doing it, and won't have their time taken up already, and works cheaply, preferably locally.

There is also the question of what broke it, and what else was cranked up in the process.

looks like it started at that reinforcement. Hard to know if a repair would work, it's conceivable given a good enough welder.

You left out the ugliness that is, basically, transversely weldign a tube.

As much as I hate to see a frame die, short of removing the whole tube and welding another back in - and that'd be the Devil's own game, I'd conduct a short service for family and friends, and then sell it on to a speciality metals recycler to be reborn as a hundred thousand other little titanium goodies.

Recycling. It's the only Reincarnation :-D

It looks like the welder undercut the tube when laying down the bead. You could try building it up again but my suspicion is that it will eventually fail again. If other joints are similarly undercut I'd scrap the thing.

"You left out the ugliness that is, basically, transversely weldign a tube."

Yeah, no question about that. But it's a second hand bike with a broken stay, gotta take a haircut somewhere. Also, as a tourer, it's the kind of question that could come up in that context. But it isn't going to look like new.