I've tried doing this with Foobar but you can still hear a slight gap between each song. Is there any software I can use to merge multiple MP3s into one and make it sound like one continuous MP3, removing any gap in between each song?

Anyone?

Have you tried Audacity? open the final merged MP3 and edit/cut out parts with gap and save to new MP3....

MP3 DirectCut can also join. You can visually remove the gaps and it doesn't re-encode if the source files are compatible. Also free.

To do a few cds with at least 12 tracks on each would take a substantial amount of time with the software listed above.

Is there software out there that completely merges mp3s into one and removes the gap in between the songs, so much that when you listen you can't hear the changeover from one song to another?

Try the free version of this and see what you think...
http://www.peretek.com/sfj.php

That 'gap' is generated by the car's MP3 deck. Get a decent deck and it won't happen. See this thread: http://club.cdfreaks.com/f48/mp3-dvd-car-without-pauses-between-tracks-226226/

Damo1888 wrote"
To do a few cds with at least 12 tracks on each would take a substantial amount of time with the software listed above.
Yeah sometimes it takes a little time and effort to get things done! or you can purchase an easier proggie...

Do you know of any?

An audio freak buddy of mine said something about Wave Lap or Wave Lab...not sure which or if it is one word.

Maybe a bit of googling will solve it, or someone else knows this software...?

I used it a few times although I'm not an audio expert more info can be found here http://www.steinberg.net/25+M52087573ab0.html

Damo1888 wrote" Do you know of any?"
Remember, google is your friend as well as mine....