And if not, you can always touch them up by painting over the errors :)
Please say that you were joking! It's NOT possible to "photoshop" lightmaps unless you have very simple geometry and low-res lightmaps (in which case you don't really need them at all).
But seriously speaking bleending is much less noticeable with decent lightmap rezz and of course most game levels are less garish than the test ones Psionic posted (I mean the red-blue-brown one). And texturing them also fades the bleeding :)