Lotus Notes Connector for Microsoft Online Meetings:
This project, created by Microsoft, contains two modified IBM Lotus Notes® mail templates (7.X and 8.5) which can schedule Microsoft Online Meetings (of Microsoft Office Communications Server 2007 R2 or the Live Meeting service) via the Notes scheduling User Interface using a REST service. The REST service along with all code and install set-up instructions are included.

The download file is a zip file containing two zip folders. One for the Lotus Notes templates and documentation and one for the REST web service and its documentation.
http://code.msdn.microsoft.com/Project/Download/FileDownload.aspx?ProjectName=LotusNotesConnector&DownloadId=13609

Architecture
Two components:
- A Microsoft Unified Communications Managed API 2.0 (UCMA) enabled web service, which communicates with OCS and the Live Meeting service. The Web Service and UCMA components will need to be deployed by the IT admins using the standard, documented procedures.
- Modified versions of Lotus Notes ”mail templates” that needs to be deployed on the Domino server, and that will automatically update client mail databases through Notes replication. When customers use the updated Notes template, the Notes client code will call the UCMA based web service.
The template and the web service allow customers to choose from any of the supported Microsoft Online Meeting types in a dialog when scheduling the meeting. The modified design elements in the mail templates are listed so you can use them to modify an existing Notes mail file. The Lotus Notes Template has been implemented using standard Notes technologies and there will be one template supporting Lotus Notes 7.x and one template supporting Lotus Notes 8.x.

You can it all here: http://code.msdn.microsoft.com/LotusNotesConnector