Depending upon your industry, a portfolio of work may be required for consideration, particularly in creative industries. It gives prospective employers an opportunity to see your style and personality come through in deliverables.
If you’re looking to make a transition from one industry to the another it may help to have a portfolio of projects that reflect the skills you bring to the table. There are a number of free and low-cost sites to build more a more formal experience than adding projects to your LinkedIn account.
Depending upon industry, you’re not always allowed to make plug your work in public spaces, so consider private postings on SlideShare that would allow you to selectively distribute deliverables via private links made available through the service.