[linux-audio-user] Loops

Hello list, I'm a new convert to linux audio having used Logic, CoolEdit, rebirth and Acid - but there is one thing that really puzzles me ... When I use one of the above windows apps there is always a loop facility where a section/region/chunk of the track can be easily looped just by selecting it with the mouse and pressing play ... I've downloaded ardour, rosegarden, gnusound, audacity, and others and none of them have this instant loop facility (er, except sweep, which is fine, but I need a loop mixer/editor like logic or acid to put my samples together). Am I the only one to work in this way? The other thing with ardour (fantastic looking) is that I can't get samples to sit next to each other (snap) unless I'm really careful with the mouse - any ideas? Thanks in advance for any advice! Andy