From: Nigel W
the phrase "necessary evil" springs to mind ;^)
Just remember, they're like you - trying to make a buck and enjoy life and be recognised for their work.
Some of em will be seasoned veterans, some will be newbies (and you can't always pick it just by their age - RE is a popular second career I think).
Some will be less than honest, others will be as forthright as they can be whilst honouring their client's mandate and some will even tell you things they shouldn't.
It is very handy to have them as much "on your side" as you can when buying. Negotiate hard but treat them politely. If you disagree with them, (which happens fairly regularly) acknowledge their views and validate their experience even if you think it's complete bs.
Everybody likes to be asked their opinion on something, and most agents will wax lyrical on their area and what's happening in it. Take it all with a pinch of salt obviously, but you can pick up some interesting info this way. Once you develop a good rapport with an agent, they will often do RP Data searches etc for you to assist.
I always ask agents whether they have investment properties themselves and where. If they know their stuff, it can be a pointer to potential sleeper suburbs.
I don't think there's any magic to it, just treat people like you'd like to be treated but stick to your numbers and remove the emotion!