RickMaddy, I have had absolutely no problem on the iPhone setting the SEL variable and using it. That's why the SEL variable exists, after all.
Code:
//Create your selectors
SEL myMethod = @selector(aMethod:);
//etc...
/*____________________________The rest of your code.____________________________*/
//
aTimer = [NSTimer scheduledTimerWithTimeInterval: 0.75 target:self selector:myMethod userInfo:nil repeats:YES];
As you see, just set it and use it as you would any other variable.