We have a metal tissue box with a removeable lid. We keep our toys in there open (like a tray), but when guests come over we just put some tissues over them and put the lid back on. We also use to have a wooden picnic box that was easy to pass as a sock storage box or something, but it ended up getting moldy when our window leaked at the last house. Very sad.
The tissue box thing works great for smaller toys, I don't think you'd find one large enough to fit a big dildo or anything though.