yes, and I find it much easier than video-conferencing (which we have at our desks using the same IM app) or phone - not only do I get a record of what was typed, it doesn't distract my my work or, erm.. surfing the web while we chatter.
video conf is really distracting, you have to stop everything to converse with the other person, and you can scratch your nose or fidget too much while doing it, at least on the phone you can yawn and wave your arms in the air to silently say "you're a moron" to the person on the other end :)
If you're worried about people abusing it and chatting all day long (you have facebook etc disabled on your net gateways too, right) then get one that will store a record of all conversations - we use Microsoft's communicator, it sends you an email transcript when you close the IM conversation (which is quite nice).
It can also be a really good tool if focussed on some part of work - ubersvn has IM chat enabled within the tool, so devs can chat about their work and comment on it, the idea being that collaboration is a good thing even for teams that don't really co-operate on the same code.