Now that Twitter has officially unveiled its Lists feature to all users, the frenzy has started. But while Lists are available via Twitter’s site, the feature has been slower to come to Twitter clients. Today, Seesmic is announcing the availability of Lists on its desktop client, Seesmic Desktop.

The new, downloadable version of Seesmic Desktop will display your Twitter lists in the left sidebar from any Twitter account you have (Seesmic lets you use one client for multiple accounts). The new feature also lets you add any Twitter user to any user list from any of your account. Right now, list functionality is limited. You cannot see lists that list you, only lists that you follow. And you cannot create lists from the client; this must be done within Twitter’s site. But, Seesmic’s founder and CEO Loic Le Meur told me that both the ability to create lists and see lists that follow you will soon come to Seesmic Desktop in the next few weeks.

The list feature will also come to Seesmic Web shortly, says Le Meur. He also said that lists took so long to incorporate