HELP!! I need ideas?!?

Ok so my boyfriend and I have been dating for awhile now and hes gonna be away in july in Hawaii (for the whole month) and Im gonna be at college taking a summer coarse before I start my freshman year of college. I always get my boyfriend, cloths, write him letters, made him a scrape book before. Now im running out of ideas and idk what to get him. I wanna get something he can remember me by when he's gone for the whole month.