There seems to be no hotter topic for discussion among Internet watchers these days than concerns over online free expression -- from the role of bloggers in advancing democratic movements, to sophisticated government censorship, to debates over how best to balance transparency with national security concerns. YouTube, Google and the Central European University will make our own contribution to the conversation at a major international conference we’re hosting in Budapest from September 20-22. We've invited grassroots activists, bloggers and vloggers from five continents, as well as representatives from NGOs, academia, industry and government to begin a long-term discussion about these issues and to form international working groups to promote practical change.

But a conversation about online free expression would be nothing without contributions from you. From election protests to government whistleblowing to grassroots advocacy, we’ve seen YouTube users upload, watch and share stories that would’ve never received global attention before the Internet era. That's why we're inviting you to submit your own video that answers this question:

"What's the biggest barrier to free expression on the Internet, and what would you do to overcome it?"

You can go to our Moderator series here to submit ideas and videos and/or to vote on your favorite contributions from others around the world. Please participate by September 7, and we’ll showcase many of your responses at the conference in Budapest later in the month. We’ll also offer highlights from the dialogue on CitizenTube.

Bob Boorstin, Google Public Policy, and Steve Grove, YouTube News and Politics, recently watched, Google's commitment to free expression