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.
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downloaded 12m 15s ago
View/Edit tags of selected track(s) in single window
downloaded 13m 51s ago
Delete characters from the beginning or ending of selected tracks' name, artist, album, comments, composer, or show tags
downloaded 14m 1s ago
Remove iTunes tracks disassociated from files
downloaded 14m 17s ago
Locates pairs of track entries pointing to the same file
downloaded 18m 55s ago
Create a Ringtone track from a selected track
downloaded 19m 30s ago
Remove selected tracks and Trash or delete their files