From what I know, you can display Adsense ads practically on any
web page that doesn't contain other advertisements of a similar
nature in terms of appearance (ads that imitate Adsense's) and
functionality (contextual ads).
If it's not allowed, the worst that can happen is that they
close your Google account. And you can always contact them about it
if that actually happens and I'm sure they'll be very willing to
assist you in any way possible.
