I took a little time styling my del.icio.us page (well, actually it’s the whole site in general). I got tired of the plain fugly layout. Although I didn’t change too much besides the colours, I think it’s more pleasing on the eyes. I also used Greasemonkey to change the background colours on the “save by x other people” based on the number of people that save it. The original background color was too light IMO, and makes the text hard to read.
I also prefixed the active tag with “{{”, and appended “}}” to the end of it. If find this styling more visually pleasing, and more obvious than the original “!” in front of it. I also hid the “!” using Greasemonkey since it also got the same styling as the active tag.