i have a glass slide and cant use it very well. it always sound out of tune. however i cover my sound with loads of delay and reverb and use it to create wierd sounds and textures. i do thing like clanger impresions and squeeks and whistles. i use this as intros of my songs and genraly just 2 give a wierd feel. i like the sounds at the start of radiohead's "lucky" and "climing up the walls" (both OKC) and use these as insperation, eventhough niether use a slide, they are done by stricking the strings behind the nut