Same here, I just upgraded to 8GB DDR2-1066 2 days ago (I had 2x2GB DDR2-1066, I got another 2x2GB of the same type)
I do find it quite useful to have.
I have a habit of not selling my past hardware, so I have a sizable collection by now.
7900 GT 256MB (dead, but might be possible to resurrect), 7900 GT 512MB (dead), 7950 GT 256MB (melted GPU), 8800 GTS 320MB, 8800 GT 512MB, 2 x 3870's, 2 x 4870's (512MB)