I have found exporting to jpg from pdf degrades the file to much or this would be a good idea, then any photo sharing site would take em.
I did use mediamax, who have just become thelinkup.com, I may have lost the files they were hosting for free or they may be in the process of transfering em !
But....just replaced one on the new site, hard to navigate but got there in the end and I do not know how long it will remain free or up.
Try:
www.thelinkup.com
Example:
http://www.thelinkup.com/shared/ieo3cob0txh5
(dont you just wish google would host this type of thing)
Or mabey Jimmy could increase the attchment max filesize for pdf's to something greater than 19.5kb, afterall .doc gets 195.3kb and strange to me .jpeg is 19.5 but .jpg is 146.5...............or zip the pdf and get a whopping 293kb attchment.
Edit: Doh! I have just zipped a pdf and only shrank it by 15% !! no help !