Is there any way to assign a variable to the dynamic_title parameter, like the logged in user’s screen name?

You should be able to do this:

Thanks Rob. That kinda works, in that when I retrieve an entry after creation via the SafeCracker edit template, it’ll pull the value into the field.

But I wondered if it could actually store the value in the database on entry creation? Right now, the Control Panel shows the variable {logged_in_screen_name}.

Ah, my mistake, I forgot that dynamic_title gets encoded before that tag gets a chance to parse. You could achieve this by setting PHP to input on your template, and:

Ah yes, PHP input parsing works great. Thanks much Rob.