This has been an interest of mine for many years because it is about taking the services to the clients.
Library 21C had small desks encouraging staff to rove
Arapahoe Libraries at Koelbel had small desks, also to enable roving
They were also making it easy for their clients to find things
At Anythink Brighton service desks are also compact
As are the ones at Anythink Wright Farms
Denver Public Library had signs about roving. They were working with an older, large building and this is one way to inform clients about what is possible, as they staff will not always be visible.