But here's my problem -- say you have some nice juicy tidbits of information hanging over the party like overripe fruit, but all they will give is the '2 gp tip,' and nothing you say to encourage them produces more vibrant roleplay? And, conversely, what if they're RPing their grimy little PC butts off, but yo honestly have no juicy rumors/tidbits to give them?
Obviously, in the second situation, you just make something up on the fly and go with it, letting the chips fall where they may and the hindmost be d*mned an all that. But, in the first situation, how do you get them more involved without just spouting off the information, which, no doubt, will quickly lead to accusations of your 'railroading' the PCs?