I've got my own reasons.
In quite a number of my presentations I show pages from the Wikipedia. I'd be
more than willing to simply save a particular page
to my hard drive and then click over to it when this is called for. However, there's
something about the way that Wikipeda pages are generated - the framework from
one database, the content from another, or something like that - that makes copying
a page difficult. Getting the content is simple, but being able to present a page
offline, and have it look like it looks online, is a problem. For this reason
I take screenshots.
Go to: Just what does it want to accomplish?,
or
Go to: As far as resources go ..., or
Go to: Don't Bogart that Info