what is rcd in act monitor

Note to self: be patient with former Windows users, as they have a reason to be paranoid about viruses... 😉

Seriously, though, there are probably a lot of things in Activity Monitor that you won't recognize, unless you're a serious Unix geek. Don't get worked up about it. In this case, a quick Google search tells me that rcd is a process that handles input from the Front Row remote. (Though, strangely, I don't see it in my process list and I have a remote for my machine...)

Here's a list of many OSX processes: http://triviaware.com/macprocess/all