My current pants are XS and they are way too big on the waist.. I need a belt and what not to keep them on. My waist size is around 30/31.
Few days ago I bought myself Burtons Poacher pants as XS - (I like the tastefully baggy style too!) - Well the XS was way too tight and definetly not baggy enough.
But I guess burtons XS would fit you fine though. I would reccommend going for S for more bagginess.
Im 5'8" as well.
I've got the Burton Groucho jacket wich is really long - its loooooooong. IMHO it looks funny when you cant
see the crotch of your pants!
Here is a size chart for burton clothing:
Burton Size Chart