There must be more than one but I haven’t found any others. It is located at the end of DenDen Town and points to the area around the Tsutenkaku Tower. No, it won’t be any use if you are hoping to spot cute girls around Osaka but it is controllable and it is live. You’ll need Java to see and control the web-cam.
Here’s the official and original page (controls are in Japanese):
and here is the same cam with the controls in English:
If you read Japanese then the original page has some information on the weather forecast as indicated by the colours displayed by the Tsutenkaku Tower.
If you know of any other web cams of the Osaka area please post a comment to tell us about it.