Google Bookmarks lets you create an online bookmark lists. I found this one in the "New Section" function. In order for this XSS to trigger though, the victim had to edit your section.
What Had to be done?The first step was creating a new bookmark list. After I got that done, I created a New section with Image tag poisioned with XSS payload. The final step was inviting the victim by giving him/her access to my bookmarks list.