If you need to bookmark some freelancers to come back to their profile later, you can add them to shortlist. You can have several shortlists, allowing you to group people by criteria, such as skills, location, hourly rate, etc.
Example: you are launching a new Internet start-up in the USA, and need to hire:
Each shortlist can include as many freelancers as you need. Feel free to use shortlists to help categorize your freelancers.
You can add notes to your freelancer to remind you why you included them on your shortlist - useful for when you come back to review your shortlists for freelancers.
Example: assumes you have a shortlist of 3 PHP developers with different levels of skills and experience.