Show current ping to website on Taksbar
Something like this? ALSEDI Pinger.
Not exactly "in the taskbar" but it keeps a record of the ping-history. Or else you wouldn't know you had problems a few minutes ago.
I know this is quite an old question. I'm currently using perfgraph - http://www.codefromthe70s.org/perfgraph3.aspx
It's free and it has more features than what you're looking for, the graph would look like this:
taskbar image hope this helps!