I have several bowls that do not have covers and covering them with aluminum foil or plastic wrap is not always convenient as it’s hard to get a tight seal and keep the food fresh.  I found these handy little Elastic Edge Bowl Covers at mileskimball.com.  You get a set of 50 covers (10 each of 5 different sizes) for $4.99!  I use mine a few times, washing after each use or you can dispose of them after each.  http://www.mileskimball.com/MilesKimball/Shopping/ProductDetail.aspx?CID=View+All&SCID=View+All&ProductID=0000083502&SiteNum=0&SourceCode=10650000002&Affid=12

Kind of like little 'shower caps'!

Nice tight seal = yummy fresh food!