Tips for Fundraising

I'm participating in a half marathon promoting research of IBDs that requires a certain amount of fundraising to acheive a monetary goal. The mileage will not be a problem to complete because I'm provided expert coaching and already run between 12 and 15 miles/week with 4 months until the race date. What I'm concerned with is generating enough support through donations in order to make the trip as desired. I have a website dedicated to fundraising and have littered facebook as well as my email contacts for donations. To be clear, I'm not grasping for donations from any Covers members. I'm only looking for advice on things that have worked in the past for others. Have any of you ever done something similar? What were the hardest obstacles to overcome? How did you succeed in soliciting donations? What angle(s) should I take when "pitching" for donations? What avenues should I pursue in order to complete this task? Regardless of your familiarity with fundraising and donations, feel free to chime in with any brainstorming ideas. I appreciate any help that can be offered.