definitely render out in single frames, or uncompressed (or any other lossless) and then use the tool of your choice to compress it (e.g. Super, Mediacoder, Premiere, Moviemaker) - after all you don't want to render it out again if some settings don't work for you. H.264 is probably one of the widest supported formats,…
oeh the jungle of codecs :D there are two ways to do this really, you can either render it straight from the software pack you are using into a compressed version, using 264h for instance which mostly turns out really well, small in size, little loss and i believe most devices are able to play this codec. but this will end…
I remember Quicktime had some codecs for solid colors, which compressed them really well, but you'd be stuck with Quicktime. When using H264 have you tried a variable bitrate (VBR) vs a fixed bitrate?