Deb - i didn't have a lot of bookmarks to begin with - maybe 50 and mostly recipes? so i spent an hour wading through them one day and pinned the ones i wanted to keep. the visual aspect is what appeals to me most. if i'm unsure of what to make for dinner a quick glance at my recipe board shows all the delicious looking food pictures.
anything that has a picture can be pinned (and there are ways to pin pages without pictures too, just have to look in the "help" section on pinterest for directions), so you can have boards for exercises, recipes, crafts, decor, really anything. i have probably 15 boards, broken down by rooms in my house and then various categories of recipes (apps, meals, desserts, drinks, etc.), then things like SIL's wedding (i'm a bridesmaid so i've spent a fair bit of time helping her gather ideas), or kids crafts for children's ministry at church. the options are endless really.
i'd encourage everyone to try it. if it's not for you, totally understandable, but i think it can be a great resource and actually provide more organization for our ideas/inspiration.
also, i don't think you have to have a facebook or twitter account to sign up. it's the preferred method, but wasn't necessary when i joined. i just used my regular email address. it could have changed though.