Twitter is testing a new feature called Lists among a handful of users.

Much like desktop app Tweetdeck, Lists enables users to create lists of Twitter accounts, grouped by interest. "For example, you could create a list of the funniest Twitter accounts of all time, athletes, local businesses, friends, or any compilation that makes sense," wrote Nick Kallen, product lead.

Lists can be either public or private. Other Twitter users can subscribe to the former, meaning the service could become "an important new discovery mechanism for great tweets and accounts," Kallen added.

A Lists API will be released in a few days, enabling developers to improve on the service. This also opens a door for Twitter to serve targeted advertising based on list characteristics, if it so chooses.

No public launch date for Lists has yet been set.