Darkmoon faire comes along every 1 month, and in that time is an easy way to make some decent cash by sitting patiently by a vendor.
Lhara - NPC - World of Warcraft
This vendor "Lhara" sells exotic goods, amongst those exotic goods are goods such as Frost Lotus, or Arctic Fur.
These items are stock items, and respawn in her inventory every 13-16 mins.
Arctic Fur sells for a good 100g, Frost Lotus for 60g.
Now some may say this is not worth the wait... but if you got something else to do, you could check back at the vendor every so often to grab your free materials and sell them for profit.
Enjoy, dont all crowd over that one vendor all at once >.>
Edit: Btw, frost lotus is only 4g from the vendor at neutral, arctic fur is 12g.
Edit1: Also she sells a bunch of other random trade materials that also tend to sell quite high, such as low lvl herbs, due to players powerleveling their inscription / alchemy etc etc on their alts.