Yes Judy you have to renew your membership but of course it's not going to be the free trial anymore. I pay $19.95 a year for 500mb space but for me it is worth it because I have family throughout the USA to share my photos.
have you tried webshots dot com? It's free and you can share photos with family and friends just like picturetrail. You also get access to tons of professional photos. They do not allow posting of pics to other websites as you do in your profile from picturetrail however.
Trevor