Sure, iTunes can join tracks, but only if they're consecutive CD tracks, and you haven't imported them. This script allows you to join any two (or more) MP3 tracks (repeat: MP3 tracks only), provided that they are the same format and bitrate.
Also see Join Together, an application that will join any type of files.
Perhaps Also of Interest...
downloaded 3m 47s ago
Convert selected tracks and replace them with converted versions
downloaded 21m 21s ago
Export album artwork as folder.jpg to Album folder
downloaded 34m 15s ago
Remove iTunes tracks disassociated from files
downloaded 50m 21s ago
Display, create text file listing info of dead tracks
downloaded 1h 34m 47s ago
Remove selected tracks and Trash or delete their files
downloaded 1h 36m 29s ago
Exports and then re-imports selected tracks' artwork