Take a week this summer in early August to travel to the geographic market where you want to work. Mass-mail firms in July saying "Here is my cover letter, I will be in the area August 9-14, I want to schedule an interview", and be sure to follow up. This will set you apart, show you are serious about the geographic area, allow you to interview early, and let you bypass on-campus interviewing and go straight to callback for some firms. They're more likely to bring you in because there's no hotel, airfare, etc. Do mock interviews with the career services office, ask them to be ruthless on your feedback, and ask them to try a few different styles of interviewing.
The more the GPA drops, the more you widen your net.