The phrase is normally "two peas in pod", but you snswered your own question. It means two people that act, think or look alike. Although no one seems to know the exacrt origin, it seems to be used most often in the southern region of the USA and also in the UK.
http://www.phrases.org.uk/meanings/40500.html
Edited by Two_Westies on May 20 2006 at 5:00 PM