If you are in need of an expert opinion to use as a source for your writing project here is a list. These sites offer services from every category you could imagine. The best part is most of them are free. All you have to do is ask your question.
HARO – Help a Reporter Out: www.helpareporter.com
Blogger Link Up: www.bloggerlinkup.com
Reporter Connection: www.reporterconnection.com
Expert Click: www.expertclick.com
If you have found other interesting expert sites please let me know.