The easiest way to share wireframes online is to use Upload and share online option in Share Online dialog. This will upload your wireframes to WireframeSketcher servers (wiresketch.com):
When sharing your wireframes you can choose to enable comments so that your clients can give you their feedback by directly annotating wireframes in their browser.
After upload finishes the link to your wireframe will open automatically in the browser. It’s a secure, hard-to-guess link. Copy it from the browser’s address bar and the share it with your team or with your clients.