Well, my watch, and many others, have tritium dials... After the Curium dials of the 50's, I doubt they'd use dangerous materials in watches nowadays.
more scientifically:
For those of you without physics/chemistry backgrounds, tritium is hydrogen with two neutrons. (like deuterium, but with one more neutron) So, in the nucleus, it has 1 proton and 2 neutrons, and around that there is one electron. In case you're wondering, its radioactive halflife is 12.3 years.
I think it's decay process is the following:
One of the neutrons kick out an electron and becomes a neutron, thus, we have Helium 3, plus some extra energy.
i.e.: H^3 --> He^3 + gamma
If you have two of them, it goes:
2H^3 --> He^3 + neutron + gamma
I rather doubt it is dangerous in the amounts used. The only type of radiation given off is light (gamma), and since we can see it, a significant portion of that energy is in the visible range. Thus, I'd conjecture that the radiation in dangerous wavelengths is less than we get from other sources (the sun, our computer monitors, etc..)
I might have some technical flaws in the above, but I'll take faith in the conclusion.
relax...