As I said before, I think Barbarella rocks. Also, I found it to be suprisingly feminist, considering - well, considering everything. On the surface it's pretty wonderful in its unselfconscious exploitation of Fonda's sexuality, but its underlying concepts are much more subversive.
Think about it. The guy that sticks around the longest in the film, and the closest thing the film has to a male protagonist. He's far from being the standard hero type; actually he's pretty useless. He walks into walls and just stands around until Barbarella shouts directions at him, which he quickly obeys before lapsing back into passivity. She thanks him for saving her life in the appropriately breathless damsel-in-distress fashion, but it's pretty clear to the audience that he was little more than an extra set of appendages.
In addition, Barbarella wastes a lot of time repeatedly rescuing him. She returns to Pygar his power of flight and tells the evil tyrant to 'decrucify the angel or I'll MELT YOUR FACE,' among other things. He never really redeems himself. True, he flies Barbarella into and out of the tyrant's liar, but the way Barbarella asks, the viewer gets the impression that he's just the quickest and cheapest mode of transportation and she could find another way if she REALLY wanted. He acts as little more than motivation for the main character.
With any strong male character there to hijack the movie from her, Barbarella is the undisputed star of the show. Yes, she sleeps with pretty much every (post-puberty) male character she encounters, but she does it without really being sexual at all. Men beg to sleep with her, and if it's in her best interests, she shrugs cheerily and says okay. Sex isn't taboo, dangerous, or shameful at all for her, so she has no resigned, defeated air of a woman with no other options - no 'weeping vrgin' stereotype. And though she often sleeps with men as a means to an end, neither does she destroy them as do exoticised 'black widow' character types.
Though the movie has distinctly pornographic overtones, it is difficult to really place Barbarella (the character, though not Jane Fonda the actress) in a traditional position of desire. There is no thrill of excitement, danger, or taboo with her, and it's much harder to desire and lust over a sure thing.