My response to a Formspring Question from Ms Suazo –
I’ve never actually had to return a promotional item. However, the ones I have, and continue to use, are items that are useful.
Tote bags are a big one for me. Many are focused on “going green” so totes are useful, environmentally friendly and will have your logo exposed to everyone who see someone carrying the tote.
Water bottles are another good one with the same sort of eco-friendly message (and very useful for workouts)
I think you have to figure out who your target customer is to see what kind of item would be useful to them. For example, if your target customer is someone health/exercise focused, maybe a gym towel might be a useful promotional item for them, or one of those little gym backpacks.