How was this solo played?

[ll00l0l]

Trey Anastasio plays an unusual solo in this song. How is it done in terms of technique? (I'm not a guitarist.) Solo starts at 3:47.

[starjasmine]

Sounds like he's using a slide.

Here's an example: Bonnie Raitt's slide solo starts at 2:17

This article runs down 15 of the greatest slide players of all time, with many video clips.

The 15 greatest slide guitar players of all time

[Bop Head]

Slide plus lots of electronic feedback.

Slide effects can beyond the use of glass or metal bottlenecks on your fingers also be created by using metal mic stands, finger rings, beer cans and bottles, knife blades etc. etc.