The Elinchrom Deflector Set is an amazing way of extending the range of options from your current light modifiers. They take up almost no space in your kit.
You can also use them with smaller reflectors, the maxilite and maxispot (the spot effect of the maxispot is greatly enhanced by removing the direct light from the flashtube), beauty dishes, all rotalux softboxes and the Litemotiv lightbanks.
Check out these videos for more information about the Deflectors and to see how they are being used: