goodroi - 11:41 pm on Feb 26, 2012 (gmt 0)
"Most Popular" is a subjective term. Some sites will show the most popular of all time and other sites will show the most popular in the last 7 days (with a secondary option to show popular of all time).
Adding a related gallery feature that interlinks old & new content outside of ajax can help. Personally I like to have some boring, old fashion text links to back-up newer technology like ajax.