Discussing a bill that would require presidential candidates to provide a birth certificate showing they're eligible, Lee Fang of ThinkProgress offers a volley of misleading statements at thinkprogress.org/2009/06/23/gop-birther-bill:

Of course, Obama was born in America and his birth certificate is widely available on the Internet. In response to an avalanche of conspiracy theories fabricated largely by Fox News and various right-wing media outlets, FactCheck.org has extensively researched the issue and provided Obama’s birth announcement in the Honolulu Advertiser, a copy of the certificate with a raised seal, and the stamp of Hawaii state registrar Alvin T. Onaka.

See the Obama citizenship summary for all the details on this issue, and here are some of the ways Lee Fang is being misleading:

1. Where Obama was born has never been definitively proven. He might be lying, or others might have lied to him. And, he's never provided any documentation beyond a picture on a webpage.
2. What Lee Fang calls a "birth certificate" is actually a "Certification of Live Birth". The former has the name of the doctor, hospital, etc., the latter does not. Here's a picture of a long-form Hawaiian birth certificate.
3. Once again: a picture on a webpage is not the same as the thing itself. FactCheck provided pictures of what they said was his certificate, but they then silently re-compressed those pictures and removed the camera data (EXIF). That data showed a creation date months before. There are various other problems with those pictures.
4. The FactCheck page with the pictures contains an outrageous lie. Despite what they say at that page, Hawaii never verified where Obama was born. In fact, Hawaii has repeatedly stressed that it would be against the law for them to do so.
5. The newspaper announcements do not indicate in which hospital or even which city Obama was born, and no one has ever provided evidence of who placed them.

UPDATE: To be precise, it's a "Certification of Live Birth", not a "Certificate of Live Birth".