I stumbled across this site a lil' while ago, & it's uber-cool. Really like all of the various runic systems that it shows, not to mention all of the fictional writing systems/alphabets as well.
It's really given me a lot of ideas as to how to design the look of various writing systems IMC look like (I liked how the Kalamar book did that as well). Also how slight changes to existing systems would reflect different languages (like the differences shown in lettering which indicates/distinguishes Dwarven from Gnomish and Orcish via the alphabet).