"Drinks or info chummer, both cost. One costs cred and the other costs favors. Too much of the former will give you a killer hangover, and too much of the latter might just kill you altogether."
A bartender contact/info broker for the Shadowrun rpg setting, can be easily adapted to any cyberpunk or other high tech campaign.
The PCs come across a wild thicket of luscious looking blackberries. They eat the berries and become drunken fools. Later they find out that the berries were part of a fae garden and were intended for fae wine. In payment for stealing the berries, the mischievious fae make life inconvenient for the PCs. Horses are untied, water skins are drained, spare clothing is drug into the water, etc.