as you can see from the replies minty there is more than one way to skin a cat (not to be taken literally, so no animal rights replies please...anyways, i have a cat...and she has her skin intact! )
you will want to find an approach (above suggestions) that will yield the greatest contrast between what you want saved and what you want cut out. if you can harness a good contrast then you can let ps do it's thing for you (lasso, channels)
otherwise you'll have to get down and dirty and do it yourself (pen tool). not that the pen tool is hard, it's rather easy. just will take longer but you will be assured of what you are cutting out.

one other helpful hint, don't always think/look at what you want saved. sometimes it's easier to think/look at what you want erased. the ying instead of the yang approach.

Comitted to excellence through art.