Yes, Celite (diatomaceous earth) is one of the organic chemist's best friends. It not only speeds up otherwise impossible filtrations, it also helps you filter out things that would go right through a fritted glass funnel or normal filter paper - something that immediately comes to mind is activated carbon (both decolorizing carbon, as well as for example Pd/C). If you have tried to filter off activated carbon using standard methods, you know what I mean - it is impossible to get rid of the last traces of suspended carbon particles in your filtrate.
Another thing that makes Celite invaluable is its ability to break any kind of emulsion you have managed to get in your sepfunnel. Just filter both phases and the emulsion inbetween through ~1cm of Celite on a buchner at the pump (don't forget to wash the filter cake with a little suitable solvent afterwards), and when the liquid collects in the filter flask, it will always be in two layers again. You will also have removed many of the colloidal particles which helped the emulsion form in the first place, so during subsequent extractions you are much less likely to get an emulsion again.