I have been seeing people writing about "hybrid fitteds" a lot lately. Basically, they are just a fitted with a layer of fairly heavy poly fleece on the outside. This provides some moisture-proofing because it repels moisture back into the diaper. It isn't really suitable for an overnight diaper (without a cover which would add even more bulk), or for going out. However, they make a great option as a sort of semi-AIO (all-in-one) for around the house or playing outside. Especially for babies who are just wearing a diaper and shirt or diaper and dress during the day. :)
I used my OS Multiwing Fitted template at the middle wing length for this pictorial. It could be made turned and topstitched or serged. I chose to do serged for the sample.
First, choose your fabrics. You'll need a heavier weight poly fleece like anti-pill or blizzard for your outside layer. Then I used cotton fleece for the middle and cotton velour for my inside layer.
Cut out your fabrics.
Mark your rise snaps (and front snaps if doing snap closures).
Apply those snaps on the top two layers only (and/or front loop strip if doing H&L).
Pin all of your layers together (in final order for serged, or outside faces facing inward for T&T).
Serged together on all but the front (for installing elastics).
Sew your elastic casings.
Add your snap-in soaker snap (if using a snap-in soaker).
Install your elastics.
Serge up the front and do any top-stitching or detail stitching.
Add your wing snaps (or hook and loop on wings).
Inside without snap-in soaker.
Velour-topped soaker snapped inside.
Templates can be downloaded here: http://prefold2fitted.blogspot.com/2012/10/online-free-downloads.html