Manfrotto Magic Arm
Ask any professional: the fastest way to dramatically improve your photography or videography is by using a tripod. Too bad they're such a pain to carry and set up (and prohibited in many public places). That's why you need a Magic Arm, especially when it's paired with a Manfrotto Super Clamp.
With this duo, you'll be able to attach to nearly anything: a chair back or table edge, shelf, railing, partition, etc., and hold your camera rock-steady. The universal joints provide infinite flexibility yet all lock down tight by turning the single manly knob. Not cheap but worth it. At B&H, the Magic Arm sells for $104.90 and the Super Clamp will set you back an additional $23.81.