Altec Lansing’s latest portable iPod speaker dock, the iMT630 Classic, features a very easy-to-pack, stylish design. Its small frame is comparable to the more expensive Editors’ choice Bose SoundLink Wireless Mobile Speaker ($299.95 direct, 4 stars), but its audio output is more comparable to—and slightly better than—the Logitech Wireless Speaker Z515 ($99.99, 3.5 stars). The …