Seesmic is having a huge week. The startup that develops Twitter and Facebook clients for the web and desktop just unveiled a native Windows client at Microsoft's Professional Developer Conference earlier this week. At the Real-Time CrunchUp today, Seesmic is launching its first venture into the mobile space with impressive apps for both the Android and BlackBerry, which are now available for download here. This is a pivotal moment for Seesmic because the startup is now conquering all the mediums— web, desktop and mobile. I sat down with Seesmic's co-founder, Loic Le Meur, to test out the apps. The BlackBerry app, which works with the devices running OS 4.6 or higher, has a extremely sleek nice interface, which is optimized for BlackBerry users with all sorts of efficiencies. You can quickly change from different timelines, easily switching from your inbox, to mentions, to direct messages. Plus, you can monitor various Twitter accounts within one appp. When you send a Tweet, you can shorten a link via Bit.ly, and upload pictures or videos via yFrog. One compelling feature is the ability to email a Tweet to a contact directly from the Tweet.