Windows only: Freeware Microsoft Outlook plug-in Xobni (that’s inbox backwards) adds a handful of killer features to its new Outlook sidebar. Among those features: Email analytics, extraordinarily useful contact cards, fast search, threaded (Gmail-like) conversations, and more. The video above gives an excellent overview, so give it a look. Seeing as Xobni has successfully made Outlook appear exciting (which is no easy feat), this freeware, Windows-only plug-in looks like a winner. Currently Xobni is in a closed beta, but the first 50 readers to head to the download page and enter the code “lifehacker” can download. Once you’re in, you should be able to invite friends, so if you use the code, keep an eye on the comments and help out a fellow Outlook user. Outlook lovers, let’s hear how it works for you in the comments.