See p. 15 and 16 of Mobile Design Elements for this and ads.

Problem

Only use when technically required... discuss this

Solution

Loading, advertising, whatever... a page that takes over when a pop-up is not called for... work carefully on this so they don't conflict

Variations

Loading screens - Try to avoid, only use if it really takes that long to load something. And usually (depends on the app) present the last stable things displayed.

In-process screens. When a delay is encountered inside an app/site/process, and the context change is so serious that presenting a loading pop-up would give the wrong impression (the old screen is gonna be wiped or is actually wrong).

Interaction Details

Usually nothing. Sometimes, can cancel.

Presentation Details

Loading indicator, which see (widget). Use time whenever possible...

Label what is being loaded, and why, and so on. Don't just say "loading"

Brand it. Advertise if you have to, but see advertising and don't confuse that with the primary message.

Antipatterns

Examples