How do you use Twitter? It seems to me the majority use it to send snippets of conversation to their followers, mini-updates of what they’re doing, or to share their recent blog posts or links they find interesting. You send @ replies, DMs, and RT’s. You’ve learned about Twitter search, and have heard that it may be giving Google it’s stiffest competition in years. In short, you’re using Twitter to it’s fullest extent. Or are you?

Now think about the “favorite” function. Those little stars next to each tweet. So innocuous that you barely give them a second thought. A tweet catches your eye, or someone lists a job your brother might be interested in, so you star it to come back later. It’s basically a bookmark in the conversation. But how many of us actually then revisit those favorites? It’s not like they’re a dogeared Austen novel or a movie you have on VHS, DVD, and Blu-ray and know all the dialogue by heart.

Here’s a revealing tool for getting to know a bit more about those you follow: go to their twitter pages and then take a look at what they mark as favorites.

Some people don’t have many, others use it as a social bookmarking tool or a repository of self-referential tweets (I’m lookin’ at you, @Scobleizer and @juliaroy!) Some of the best examples of using Favorites (or, for some unknown reason ‘favorites’ when looking at others’ pages) are @alessandraco and @xenijardin. Both have a mix of useful things that they wants to save for later, blog posts, and generally neat stuff.

There are actually a few services out there that combine Twitter with some bookmarking functionality, such as twitticious (a downloadable program) and Tweecious. But would it be a good idea for Twitter itself to offer some more robust bookmarking functionality to go along with its Favorites section? Adding search and ranking capabilities would be the simplest solution, but unless Twitter can find a way to monetize the added features it’s unlikely Twitter would layer in such bookmarking options directly.

Giving users or brands a way to benefit from the social analytics that could arise from bookmarking capabilities could be a viable monetization option, perhaps as part of a suite of premium features. So would it then be enough to storm the walls of Delicious or Magnolia? Could Twitter truly be a giant killer in all realms?

Matthew Kraft (@MKraft) is a Social Media fan boy. This is his first-ever guest blogpost. Currently prepping a Twitter Tools blog, to come out this summer.