Try ScholarshipPoints.
ScholarshipPoints offer monthly scholarships for students of all ages, along with several special scholarships throughout the year that all students are eligible to apply to. In addition, they also have a search engine to look for scholarships.
I am also a college student myself, so I understand what you mean when you say that scholarship opportunities for undergrads are very limited. I have been using ScholarshipPoints now for just about a year, and as they have grown in membership, they have continued to add additional scholarship opportunities.
Anyway, here is the site:
ScholarshipPoints