Over at Astronomy Picture of the Day they have this beautiful picture of the Cosmic Microwave Background - Beautiful.
They point out that the dipole nature of the colors you see are due to us moving "600 kilometers per second relative" to it. See that's bothersome to me. To me it implies that there is a preferred "stationary" frame of reference. Such a thing is contrary to Einstein's Theory of General Relativity.
(For those versed in the theory, Yes, "contrary" is too strong a word. But certainly there is an implied preferred frame which is not supposed to exist.)