Does anyone know any good apps for viewing large pdf files/books in iPad? I'm a designer, my consultants and clients usually sends me drawings in PDF format that has a lot of vector lines. I use Bookman, iBooks and Stanza to view them but they take forever and lags and sometimes crashes when viewing those PDFs. The files are not even that big, they are just +/- 250k but consists of a lot of vector lines. Any suggestions?