Apologies if this has already been raised:

But I would love to be able to search for a character name and find where they last posted to know where they were (in game).

The immediate problem I can see with that is that their last post might be in an OOC thread, which wouldn't tell you anything about where they are IC.

It could include the date of the last post. Which, if its been a long time, goes a huge way to knowing what to skip over. Even if it was an OOC post it eliminates XXX number of recent days. Presumably if the character has been forgotten XXX is large not small.

That information is already available, in the Cast List.

Also if you have a decent browser you can open the entire thread (if isn't too long) and just CNTRL-F to search their name.

That's how I stay on top of things.  Not sure if that would work for the more mobile users...