If you’re a fan of the online bulletin boards known as newsgroups, you’ve come to the right place. The Mac is crawling with newsgroup-reading programs. Microsoft Entourage, for instance, has one built in. In the shareware world (try searching the Mac App Store or www.versiontracker.com), you can take your pick of MT-NewsWatcher X, NewsHunter, and Halime, to name a few.