Sparklines
Jon Udell recently posted about Sparklines :
Here, for example, is a
sparkline showing monthly citations of LibraryLookup in del.icio.us since Jan
03: 
. I made this using Joe
Gregorio's excellent sparkline service, by the
way.
Grig
has some cool
examples
as well:
Here is the per capita income in California from
1959 
to 2003.
And here is the "real" per capita income (adjusted for
inflation) in California, from 1959 
to 2003.
Edward
Tufte proposed Sparklines: "small, high-resolution graphics embedded
in a context of works, numbers, images". The idea is to use small graphs to help
us view trends and integrate them into the content. Tufte proposed them a few
years ago, and it's neat to see them in the wild and supported on so many
development platforms.
Jon Udell made use of a simple service which allows you to specify a
sparkline using an image url with querystring parameters like
this:
http://bitworking.org/projects/sparklines/spark.cgi?type=smooth&d=88,84,82,92,82,86,66,82,44,64,66,88,96,80,24,26,14,0,0,26,8,6,6,24,52,66,36,6,10,14,30&height=20&min-m=false&max-m=false&last-m=false&min-color=red&max-color=blue&last-color=green&step=2
There's plenty of .NET code out there for creating
Sparklines: