The Giottos MH7002-630 Ballhead is a single action ballhead suitable for travel use, with a 'snap-in' quick release system that's also got a bubble level right at the plate's location. It uses a simple single lever to lock and unlock all movement functions, and is rated to comfortably hold equipment weighing up to 11 lbs (5kg). You can use your SLR camera comfortably with a ~200mm lens.
The MH7002's strong locking lever can be adjusted so that the range of movement between locked and unlocked is wherever you prefer it to be; many heads cannot be adjusted in this way.
'Single action' ballhead with locking lever that controls the release of all head motion
Locking lever can be pulled out and repositioned, so that the motion range is to your preference
Appropriate for use with SLR cameras and lenses of up to approximately 200mm
Two-stage quick release system helps prevent accidental opening of adapter
Rubber-covered quick release plate with anti-twist video register pin
Dual bubble levels right at the base of the quick release adapter
Compact 2" (50mm) base diameter