This page:
http://beagleboard.org/angstrom
has some links to mirrors of the angstrom distribution.
But it seem that the link you are supposed to download:
Angstrom-Cloud9-IDE-GNOME-eglibc-ipk-v2012.05-beaglebone-2012.08.14.img.xz
is broken on the mirrors.
The download starts on the "Original" page, but it always freezes for
me long before
it can complete (though this issue could be my internet connection
doing somehting
stupid for all I know).