If you're uploading to pet hobbyist (kingsnake) when you run out of disk space you just can't upload any more pics. Most photo hosting sites are like that.
How many pics are in 1000k depends on the file size of the pics. If you right click on the pic file and go to properties, it will tell you how big the pic is. The .jpg format is used by most digital cameras and can store pics with a relatively small amount of memory. I can have decent looking pics that are as little as 30k, but I have to resize them. Without resizing or lowering the quality (something you can do with .jpg), my camera takes pics that are something like 200 or 300k. Most cameras come with resizing software.
Also, keep in mind smaller is kinder when you're emailing photos.
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"The serpent crams itself with animal life that is often warm and vibrant, to prolong an existence in which we detect no joy and no emotion. It reveals the depth to which evolution can sink when it takes the downward path and strips animals to the irreducible minimum able to perpetuate a predatory life in its naked horror."
Alexander Skutch