Miles to DD Mall are "supposed" to take 4-6 weeks, but i never wait more than 3 for my miles to post.
Agreed on the rawhides/music downloads...another good one is overstock.com...you can get something dirt cheap with $1 shipping and pick up a few miles.
And then of course...there is the notorious FTD flower shop...SP is yours for $1250...(just kidding...i hope you don't do this)