Bubble charts are built in. They are essentially the same as bubble charts
in 2003.
Waterfall charts are not built in, but they are an extension of floating
column charts, which are stacked column charts with some series made
invisible to give others the appearance of floating. I have general
instructions on my web site, which were written with Excel 2003 in mind, but
which can be created the same way in 2007 using the respective commands.
http://peltiertech.com/Excel/Charts/Waterfall.html
- Jon