I have a relationship that shows the other users who are logged on in a portal..

I'd like to arrange the output so that the users aren't listed in a portal, but

are listed similarly to how they're listed on this web site...

Other users logged on: Tom Smith, Joyce R., Bob C., Frank A.

Can I somehow concatenate the records that would otherwise just show up as rows in the portal ?

Create a value list based on the related full name field. Then create an unstored text calculation of Substitute( ValueListItems( Get(FileName); "yourvaluelist" );

Ah.. cool! I may be asking for a lot here.. but I might as well ask.. will this update dynamically ?

i.e. if someone logs on.. will the related value list change to reflect that that person has logged on ?

is there a way to make it so that it does ?

as is, the portal does (kind of) update dynamically... though it "sticks" sometimes..

Once someone makes a change to the current record or creates a new one, then it will update. You may need to force a refresh of the screen using Refresh Window [Flush cached join results].