If a virtual cache REQUIRED you to take a picture of you and your 
GPS (or something like that) in order to receive credit for that cache.. 
 
However, you don't need to use a digital camera to take a picture and post it to Geocaching.com.  You can get a very inexpensive camera (like a disposable camera for around $5), take pictures, develop them using a service that provides you with free pictures online (like Photoworks.com), 
and upload the online picture to your cache log.  This is what I did for virtual and locationless caches before I obtained my digital camera.
 
This is not as easy as using a digital camera, and you may have to wait several days after visiting a virtual cache before you can obtain the picture and post it to your log entry, but it is an inexpensive way to get a picture for a virtual cache entry.
 
Ken (a.k.a. Highpointer)