A friend asked me whether I'd ever talked about salary with any of my colleagues -- you know, getting an idea of what people are making, etc. I said no. Is this something you've done?

This really is a big no-no. I work in HR and sometimes wish I didn't know people's salaries. It can cause a lot of animosity to know what your coworkers make. I see a lot of underperformers that make a lot of money and it can be frustrating. On the flip side, I see a lot of people who work really hard and make very little for their efforts. This can be equally frustrating.
Take it from me, you don't want to know what your coworkers make and you don't want them to know what you make. In this case, ignorance is bliss.

I don't really want to know what SOME people make, but some of the ones I talk to a lot and do the same quality of work I do (just have more years than I do), I try to get a ball park figure out of them. I never directly ask how much someone is making.Like I'll say, oh in 5 years I wonder how much to expect. Typically I'll get the 'oh when I started and after that long I made between XX and XX K a year. So that gives me something to go by. Some people I just don't want to know because I know it's more than me (I'm only 22) but they are so terrible at their job that I'd feel bitter.

ironically, i never want to know - but for some reason people always tell me these things! i dont discuss my salary unless it's with my boss or people i dont work with. i think marcia has a good point if you are looking for a ballpark of what to ask for when entering the work force (no matter what your age ;) ) or changing jobs etc. then that is completely different

In nearly every instance that I've seen people do this it has back-fired on them. I would absolutely advise against it.

I would advise against it as well. Part of my job has been HR for several years, and I would get very frustrated with people who discussed their salaries. It inevitably led to problems.

I worked at at job where underperformers were paid more than me. They were also of a different race and I had to train them. Knowing this information that I didn't ask to know about has caused me tremendous grief in the workplace. I resented the company as a whole and I don't trust employers at all. I was also told that when companies don't like to discuss salaries it means that they usually don't pay fair.

I say this is a huge no-no. It never leads to anything good. I wouldn't even tell a co-worker how much I'm willing to spend on a new apartment - talking about money and how much you spend on what is just not a good idea

I don't care what they pay "Mr. ladder climber" in the cubicle next to me. I keep up on what my work is worth through the US dept of Labor Statistics. www.BLS.GOV click on the pay and benefits tab, then click wage by area and occupation. It is totally appropriate to discuss with co-workers what the industry is paying for your skillsets. When you say to your boss, "according to US labor beaureau statistics- the service I provide can be marketed at 50K in our geography. As you know I am currently at 40K. I love my job here, how can we work together to fill in this gap?" They will respond. I have also learned to have my negotiables planned. 4 day work week? Education? what else can you ask for that matters to you?