Greg Martin of the Kentucky Headhunters does some nifty slide work and even has a video out demonstrating how he works his magic. He's typically categorized as "country" but his roots are in blues-based rock 'n' roll. www.gregmartin.com

Ditto Warren Haynes of Gov't Mule. Beware, Gov't Mule rocks hard and heavy...not for the faint of heart or those who're not willing to sacrifice their aural faculties. Haynes did a stint with the Allman Brothers during one of their incarnations. Made loud to be played loud - but excellent slide work on selected songs...straightforward, hard-drivin' blues-rock.