The panoramas are usually 2-3 MB and takes 10-20 seconds to download if you are on a broadband connection. If you are on a modem connection then it can take 5 minutes or more for each panorama.

About Plug-ins:

To be able to see the panoramas you need some kind of plug-in installed in your browser.

You need either: DevalVR, QuickTime or Java. Panoramas from mid 2008 or later also come in a Flash version.

You will get the best viewing experience if you use the DevaVR-viewer.

Another good viewer is QuickTime from Apple. It is however a much larger install than DevalVR.

Most panoramas also come in a Java version. Java is a rather common plug-in so chances are it is already installed on you PC.  Beware that Java often takes long to start, often 10-20 seconds before you see the Java logo.