So basically, the standard 'any business that competes' language? That is rather vague and open to interpretation. Is another iPhone OS company in competition even if they dont make the same kind of software? Your current employers could certainly make a strong case for that. Unless it is specifically spelled out in the contract well, that is why we have lawyers and courts- to settle the ambiguities in and different interpretations of contracts.
Basically, you won't know unless they try to enforce and either succeed or fail.
