You can stream the imagery in the Oregon Imagery Explorer through a Web Map Service (WMS) or through ECWP . 

WMS is a convenient way to bring in high resolution imagery into  applications that support WMS (i.e. GIS, web applications) thus, eliminating the need for a copy of the source imagery.

The following URL can be used to specify the WMS service within an application that supports WMS (i.e. ArcGIS 9.x):

 http://wms.oregonexplorer.info/ImageX/ecw_wms.dll?

NOTE:  This link will not by itself display imagery.  You must be in an application that supports WMS requests.

Please see the Tutorial (PDF) for the Oregon Imagery Explorer WMS for more information.

Quick steps to add Oregon Imagery Explorer imagery into ArcGIS 9.x:

1. In ArcCatalog click on GIS Servers -> Add WMS Server.

2. In the URL: box, type: http://wms.oregonexplorer.info/ImageX/ecw_wms.dll?

3. Click "Get Layers".  You will see a list of the images in the WMS and the supported projections.

4.  Click "OK".  A newly added WMS service will be added to ArcCatalog called "Image Web Server on wms.oregonexplorer.info."

5.  You can either click on the  newly created connection and drag the Image Web Server into ArcMap, or in ArcMap select the wms service from the "Add Data" dialogue box.