Just curious, has anyone ever used those Rosetta Stone thingys? They tell me they're good, but I'd rather hear it from an impartial source.
We have Rosetta Stone set up on the computers of our lab for students who are learning English, and it's the first program I generally show to students, especially if they know little to no English.
I think it's a really great way to start learning another language outside of just jumping full bore into a class. One of its big strength is its ease of use - the interface is really easy to use and not clunky at all (which is important here, where a lot of students who are just learning English usually haven't used a computer much).
RS, I think, is good for building vocabulary (especially since it links what you see with words and phrases), conversations, pronunciation, and writing. Where it's probably weakest (in the version that we have) is with learning grammar, which isn't its goal at all.
On Ebay, you can find starter packs for less than $10 (maybe even less than $5) that have a sampling of the first round of exercises and activities. You might want to check that out first and see if you dig it enough to commit to the full program. Actually, I think by now there might even be downloadable demos on their website.
Overall, though, just like anything, it usually depends on how much time you can put into it ...