Well, if you have a 10k fixed resistor in an RC circuit - say like a decay control - you could get 1/10th the time constant by using a 1k resistor, or ten times the time by using a 100k resistor. Except, you won't, exactly, because other parts of the circuit will interact.
Furthermore, if you wire a 100k pot in series with a 1k resistor, then you'll get a variable decay that can go from 1/10th normal with the pot at minimum (1k only) to ten times normal (1k fixed, in series with 100k pot - tolerance will place it around 90-110k because they're fairly loose). However, the "normal" 10k setting will be about 1/10th of the rotation of the pot - think about it. So, the useful range will be all up one end. Of course, this is why we use logarithmic pots, but even so you wouldn't have a particularly linear response - you wouldn't be able to mark of even divisions of time.
If you're not too bothered about precision timing, you might not care.