Yes you can. Remember that the voltage is alternating. 240V is actually ~240V. When the UK downgraded from ~240V to ~230V there was a lot of nonsense talked about certain appliances 'running slower', but we happily used the same devices.
A lot of electronic stuff is dual voltage -- and marked as such -- and just works of course. I found that nearly all of my UK-bought computer related stuff just worked in the US once plugged in with an appropriate adaptor.
A surprising amount of electronic kit which is marked as 240V only also works fine at 110V with no transformer needed. Examples are various radios, a small hifi and a pair of powered computer speakers. There doesn't seem to be any danger in trying this going in the 240V - 110V direction, doing it the other way around wouldn't be a good idea of course.
Ordinary incandescent light bulbs work but are around half as bright as normal. One surprise is that all the low energy light bulbs I've tried have worked fine -- I guess a lot are probably dual voltage and just not marked as such.