Hello Benjamin,
Mango does not currently use bar graphs, but other types of trend information are available in multiple ways. As Keith mentioned, there are graphs available on the point rollovers in both the watch list and in graphic views, as well as in reports. There is also a mutiple-point graph at the bottom of the watchlist. Larger, individual point graphs are also available on the point details page.
I'm not sure that this answers your question. If not, feel free to inquire more.