The online classes offered at the Extension School are the best online classes around. But don't be fooled into thinking that taking classes there will help you to get into Harvard. The classes are open-admission, so anyone can take them. If you do very well, you can apply to the Extension school as a degree candidate, but even then, with a degree from Harvard University - only 3% graduate - only 2 undergraduate extension degree students not previously affiliated with Harvard have been accepted into HBS in the last 10 years. Countless Harvard College graduates are rejected from HBS every year as well. Once accepted into any of Harvard's schools you can obtain special student status that lets you cross-register and take some of your classes at HBS for instance. But to answer your question, no. Simply taking a few of the Extension or Summer school's distance offerings won't add much to your resume. But take the classes anyway, they'll challenge you intellectually and give you an idea of your Harvard classes should you get in. Good luck!