I assume that you are referring to Windows Live Mesh, not Live Mesh -
www.mesh.com, you are in the wrong forum.
For discussion of the new Windows Live Mesh (formerly Sync), (as well as the released Live Sync version) go here:
http://windowslivehelp.com/forums.aspx?productid=24
Live Mesh beta (going away at the end of March 2011) has the Live Desktop at
www.mesh.com - you can access this from any PC to upload/download to/from. you would not modify files "on the site" if you mean edit a document. You download, edit, upload.
Windows Live Mesh uses SkyDrive. So, as long as you have designated that folders are synchronized to the cloud storage, you can access the SkyDrive copies at
http://devices.live.com and selecting the folder or by going to
http://skydrive.live.com and selecting "view synched folders" from the choices at the top of the page.
-steve
~ Microsoft MVP Windows Live ~ Windows Live OneCare| Live Mesh|MS Security Essentials Forums Moderator ~