collectd can spit out rrd files, and there are tons of rrd graphers out there. I use drraw... it's really old and boring, but I like it for it's simplistic and

collectd can spit out rrd files, and there are tons of rrd graphers out there. I use drraw... it's really old and boring, but I like it for it's simplistic and I am used to it. (it's just a perl script you run on your web server, no DB needed)