For a project that we're too engaged with, students and I are exploring graphing server solutions. We started with rrdtool and quickly found cacti. But a student pointed us toward graphite, and I really didn't want to rediscover how to install every time we wanted to test it. So I've scripted a solution. I suppose they could be build notes toward a TKLPatch. Script on next post.
Graphite docs are here: http://graphite.readthedocs.org/en/0.9.10/.
We like: the API (nicely documented); the RRD alternative is nice and seems very quick and efficient.