Echoes: The Best of Pink Floyd places "Jugband Blues" after "Wish You Were Here" (and, like the rest of the album, adds Fading into the Next Song). The more obvious connection between the two is that "Wish You Were Here" was a tribute to Syd Barrett, and "Jugband Blues" was the last released song Barrett wrote for the band. However, "Jugband Blues" has also been interpreted as Syd's sarcastic response to being kicked out of the band, so placing it after "Wish You Were Here" almost makes it sound like an Answer Song that happened to be written before the song it was a response to - especially because the first verse has the lines "And I'm much obliged to you for making it clear/ that I'm not here".
Speaking of "Echoes", a possible interpretation is that it's about the evolution of communication. Given that the third and final verse could mean the future, and that it occurs 15 minutes after the second, it could represent how the future seems more abstract or far-off than the past.