I'm assuming it's already shot in which case very difficult. If it's fairly gentle movement then you've got a chance else isn't really possible to get a perfect result.
There's a few bits of software, some free upto expensive, Dynapel Steadyhand is one, do a search here under 'stabilisation' as this comes up pretty regularly.
To state the obvious, much better to get the camera stable. That's why people pay lots for Steadycam rigs and also pay a lot for operators. If it really could be fixed in post Hollywood would be doing it!
Sometimes, if it's just a shot or two, making it slow motion slows down the shake and it doesn't look so bad. The shake reducing algorythms I've seen (on Avid systems) lose quite a bit of resolution. Maybe with HD there will be enough extra video to do this less objectionalbly.
This comes up all the time. The three products mentioned are:
Steadyhand (from Dynapel)
Steadymove (only works with AfterEffects and Premiere)
DeShaker (a free VirtualDub plugin)
Do a search in these forums and you will find LOTS of discusssions of these products. Steadyhand is used the most, but lots of people use DeShaker. Don't forget to tell the program that your material is interlaced.