I wrote a hub a while back on "50 Ways, Topics & Ideas to Write A Hub or Online Articles"
Some include:
Write a hub on your worst date, EVER!
Write about your favorite places to write your hubs; your porch, the coffee shop, etc.
Write about your favorite websites that you use online.
Get ideas by searching through news message board forums where people have constant discussion about the issues.
Write about your favorite form of exercise.
Write a review on your town or a major city in your country or state.
Concoct your ultimate dream vacation and write a hub about exactly what you'd do there.
Read National Geographic and other travel magazines to inspire travel hubs.
Look through flickr to gain inspiration on topics.
Write about your favorite season (fall, winter, etc.) and why!
Write about the characters from your favorite television show.
Hope these help!