How and for what to use SP-GIST?

Hello

The release notes of PostgreSQL 9.2 praise "SP-GIST" as a major feature
but I cannot find any information on how to actually use it.

The main documentation seems unusual low level and the examples chapter
just refers to the source code. The only examples I can find there are
the regression tests.

In those I stumbled across the "~>=~" operator. How does it differ
from the normal ">="? (kind of hard to google for this string :))

SP-GIST should be good at "suffix search", I read. What exactly is
meant here? I assume its not suffix as in "LIKE '%foo'".

I'm interested because I heavily use the prefix_range extension for
phone number searching. Could I somehow benefit from a SP-GIST suffix
index (maybe by reversing my numbers)?

thanks for any comments!

bye,

-christian-