The Challenge Magazine PDFs are excellent digital reproductions of this classic RPG magazine. The page and cover scans range from good to excellent quality (the covers may show some signs of wear from the original), and all text is fully searchable. I just wish they had gone the extra step to bookmark them as well.

This particular issue is the all-Traveller issue, and features skirmish rules, quick-start PC generation, and several adventures and articles for Traveller: The New Era.