The following title ideas were taken from the NaNoWriMo "Adopt-a-Title" forum thread. Most of them I just took because they sound cool, and I may (or may not) use them someday. The comments in parenthesis are mine.
The Quiet You Leave Behind (good romance novel title.)
Visions in the Thorns (possibly romance or a paranormal novel.)
Missing Rose (this would be perfect if I was writing a doctor who fanfic. which i'm not.)
Life Like Glass (this one would work well with a "disease of the week'-type story, either ya or adult.)
See You At My Funeral Tomorrow Evening (another good ya title; could be serious, could be wry.)
Shards of Broken Minds (possible psycholocical thriller. or horror.)
Ghost Walk (this might work for a ya novel with paranormal overtones. or maybe a dead person commenting on the people he/she left behind.)
A Not-So-Unique Snowflake (definitely ya. it positively screams ya!)
Blame It on the Weatherman (most likely a comedy in the vein of douglas adams.)
A Universe In My Teacup (another good doctor who fanfic title, but i'm not writing a doctor who fanfic. no i'm not!)
A Rather Short Tree (a story about midgets? hobbits? the memoirs of the shortest kid in the 5th grade?)
P.S. "ya" stands for Young Adult, in case you're wondering.