I just recently stumbled on the Loganberry Books site, where you can submit queries about books you may have forgotten the name of, but still remember what the book was about. Do you have one that would stump the booksellers?
My book would be one I read when I was growing up. I found it in my grandparents basement, so it must have belonged to one of or all of my aunts at one point. It had a seafoam green cover and was about two girls, probably junior high age. I think one moves into the house next door and they become best friends, with extravagantly fun parties and dress up. There's some scene with a pool, like it gets filled with flowers or something? And then one moves away and maybe there was a divorce or single parenting on one side, which made the other family uncomfortable?
Anyway, it was a good book, but I could never remember the name and I'm not so sure I remembered the plot so well either! My more recent book search/memory jogging was when I was updating my Shelfari shelf. I really wanted to add this book I had enjoyed, which featured a few (I thought) key phrases that would surely turn up the book in a google search: New Mexico, peacocks, teacher, environmental land abuse, father is a doctor, seven sisters.
I asked people about it and would search every so often. Then one day I was looking through my books and realized I had already added it. It was Animal Dreams by Barbara Kingsolver. Idiot.
It is a good book, I highly recommend it:) Photo from here.