If you are using Visual Studio with Team Foundation Server; Annotation is the new feature in Orcas; simply right click the source and choose Annotation from Source Control menu. Its SubVersion' Blame like feature with which you basically get the info that who wrote each line in the given source file and when? The cool thing is; when Annotation is "on" you can view the change-sets (details of all files in that particular commit) to get the understanding what other things got written along with this line). Its really great help for code reviews!
This Annotation works with 2005 Team Foundation Server as well!