Send and receive Skype calls on your BlackBerry using iSkoot's excellent Skype client. Sound quality is better than you'd expect -- even on slower 2G Internet connections -- and iSkoot's tabbed interface makes navigating your contacts list easy. ISkoot also allows you to chat by text, if you prefer.
It also integrates nicely with your BlackBerry's regular phone settings, using your existing ring tones and the BlackBerry call log.
Don't fall out of the Twitter loop when you're away from the computer. TwitterBerry from Orangatame Software lets you read all the latest tweets from your Twitter friends, plus you can send tweets, read and write direct messages, and view your @ replies.
Menu items let you call up your BlackBerry's spell checker (so you don't embarrass yourself) and insert symbols easily (so you can make the most of your 140 characters). You can also view your friends' timelines individually, as well as the public timeline of all Twitter users.
(Need tips for using Twitter? See "Twitter for business: 5 ways to tap the power of the tweet.")
CallWave's WebMessenger lets you chat with friends or business contacts on the most popular IM networks.
You'll need to create a single "master" account to log into the software, but once logged in to WebMessenger, you can log in to your existing accounts with AOL, Google, ICQ, Jabber, MSN, Skype or Yahoo.
WebMessenger downloads your buddy lists so you can see at a glance who's online and start chatting almost instantly. Depending on the abilities of each particular network, you can create chat groups, send messages to multiple recipients, and add or remove contacts, just as you would with a desktop client -- making WebMessenger a solid alternative to desktop chatting.
Logan Kugler is a Los Angeles-based freelance writer who has written about technology and business for more than 30 national magazines including MacLife, PC Magazine, Success and Advertising Age . You can reach him at email@example.com.