Even if you're not looking for a career in non-profit, donating your time can be a great way to increase your skills and gain some credibility. Most organizations need help in several areas. If you're trying to break into a creative field, this can be your opportunity to develop a writing, design or marketing portfolio. Don't be afraid to ask your supervisor to give you a written reference. Spending time as a temp gives you the opportunity to try on different positions and companies to see if you like them.
Many employment agencies have long-term positions and skills training available.
Agencies often work with large corporations, which will look good on your resume and may lead to permanent employment. Some companies, like MTV, have their own Temp pool. If you're interested in a particular company call human resources to see what options are available. If going back to school is part of your plan, look for programs that offer an internship. Generally, an internship is arranged through the school.