This little fella has been hanging around for a week or so at a park about 25 miles away, so I thought I probably should go pay him a visit. Northern shrikes are common enough in this area, but Loggerheads are considered quite rare this side of the Cascades, so seeing one was quite a treat.
Zombiesniperjr, the most obvious difference is in the band across the eye; On the loggerhead, it's darker and extends above the eye, and across the bridge of the beak. On the northern shrike, it doesn't. Also, the loggerhead had a darker beak and a larger head, though those are harder to judge unless you see them together. Here's a shot of a northern shrike for comparison...