Two sites that enable you to make a comic strip online (As always no responsibility is taken for contents of external sites):
Comics @ Mai’Nada.Net – Sketch your imagination
This is one that enables you to do your own drawing online. Click ‘create a comic strip now’ to get going. The problem with it is that doing the drawing yourself with a mouse means that its very difficult to get satisfactory results. But good fun nevertheless.
Quicktoons enables you to make a comic strip without needing to draw anything by selecting backgrounds, characters, speech bubbles etc. The advantage is that no drawing skill is needed, the disadvantage is that the comic elements are very limited indeed. It took me a while to figure out what I was doing too, but then I am a bit slow.