Did you know that you don't have to ask members of your guild for links to their professions?
The professions browser was added as part of the World of Warcraft: Cataclysm expansion. To get started, all you have to do is open up your guild window (default hotkey: J), select the roster tab, and then click on the dropdown box to change the view to professions.
You are now viewing your list of guildmates, sorted by profession. You can expand any profession to see what guildmates practice that profession and their current skill level. You can select a specific character to browse through all of their recipes/patterns/plans, or click on any given profession to find all of the recipes available to the guild.
Note that you can filter each character's profession list by clicking the filter button. The profession browser makes it easy for guild members to pool their resources -- try it out today, and you might even be able to help your guildmates level up!
We're always on the lookout for useful functions in World of Warcraft that seem overlooked. Do you know of one? Tell us about it in the comments below.