Below are the ten most-viewed Gray on Claims posts from 2009.  Popular posts from the last year include my joint study with Hal Wegner concerning increasing domination of the patent system and posts summarizing local patent rules affecting claim construction.

1. Top 150 "Customers": Increasing Domination of the Patent System (link)
2. Summary of Local Patent Rules Affecting Claim Construction Practice (link)
3. Patentee Describing Single Embodiment as "The Present Invention" Leads to Narrow Claim Constructions (link)
4. Federal Circuit Construes Term Found in Specification but Not in the Claims (link)
5. Federal Circuit Uses Claim Differentiation, Declines Limiting Claim Scope to Preferred Embodiment (link)
6. Federal Circuit Holds That False Marking Statute Applies on a Per Article Basis (link)
7. BPAI Uses Dictionary Published Six Years After Filing Date in Rejecting Claims (link)
8. Northern District of Illinois Proposes Patent Rules Affecting Claim Construction Practice (link)
9. Prosecution History Used to Limit Method Claim to Performing Steps in Specific Order Claimed (link)
10. (tie) BPAI Holds Term Indefinite and Summarizes Reasoning Behind Broadest Reasonable Interpretation Rule (link)
11. (tie) Google Creates its Own Dictionary: Will it be Used by Patent Practitioners? (link)