We study the gravitational time delay in ray propagation due to rotating
masses in the linear approximation of general relativity. Simple expressions
are given for the gravitomagnetic time delay that occurs when rays of radiation
cross a slowly rotating shell and propagate in the field of a distant rotating
source. Moreover, we calculate the local gravitational time delay in the Goedel
universe. The observational consequences of these results in the case of weak
gravitational lensing are discussed.Comment: 15 pages, 1 figure, revised version submitted to Phys. Lett.
