You make a file in iphoto and name the file whatever you like. Drag the pics from your library in the file. I have thousands of pics in my iphoto library and do not want all of them on my phone. My phone has 3 folders for now
1) Library
2) contact pictures
3) iPhone wallpapers
(1)All pictures loaded to iPhone will go into the library file automatically.(2) I have pictures of family and friends and when phone rings I see the picture and know who is calling.(3) As I find wallpapers I like put them into the wallpaper file and change wallpapers every day or so. On the itune sync page I check only the files I want to sync to phone... the 3 I mention above. You can have many files..