Convert your pics to indexed

[Sgt. Groovy]

...when appropriate. You can shrink the size considerably when you convert a png from full RGB to 16 colours indexed. For b&w line art this usually doesn't decrease the quality noticeably, the white may get a slight yellowish tone but it doesn't matter with pictures posted for demonstration purposes. You can try even 8 colours, and if it still looks good, post that instead. All this will save your upload quota, the server bandwith and the time of people with slow connections.

Indexing doesn't work well for shaded images, you either get banding or ugly dithering.

[Sgt. Groovy]

For clarification: I meant make an indexed version of images for posting.

[zookeeper]

Just remember to not do this for finished images, ones that are supposed to get committed or to be worked on by someone else. Should of course be fine for showing WIP stuff.

[wayfarer]

...when appropriate. You can shrink the size considerably when you convert a png from full RGB to 16 colours indexed. For b&w line art this usually doesn't decrease the quality noticeably, the white may get a slight yellowish tone but it doesn't matter with pictures posted for demonstration purposes. You can try even 8 colours, and if it still looks good, post that instead. All this will save your upload quota, the server bandwith and the time of people with slow connections.

Indexing doesn't work well for shaded images, you either get banding or ugly dithering.

Or just use imageshack.

At least I do it, we don't want to waste precious space for trash do we.

[Artis]

...when appropriate. You can shrink the size considerably when you convert a png from full RGB to 16 colours indexed. For b&w line art this usually doesn't decrease the quality noticeably, the white may get a slight yellowish tone but it doesn't matter with pictures posted for demonstration purposes.

Make sure that the image is greyscale (desaturate, convert to greyscale, etc.) and there won't be any color casts.