I just watched...
Starring Sandra Bullock and Keanu Reeves.
Sweet and touching in a Time-Travellers-Wife(Girlfriend)-Sandra-Bullocky sort of way.
Her hair in 2004 was bangs, long, unstyled, fairly unattractive. Her hair in 2006 was shorter, with longer bangs, styled and quite "cute" (if I can use that word).
At one point in the movie she refers to her hair in 2004. "I was having a bad hair year that year." (Gotta love someone who is self-aware!)