During the time of ValenToon's Day, the treasures become Hearts. They are worth double the laff they usually are. This is very useful while fighting the Chief Financial Officer, since the goons will also drop these hearts.
When a toon with full laff points encounters a treasure, the treasure fades away and returns. The toon will be unable to earn any more treasures unless they have at least one laff point away from the full meter.
In Beta 1, there were treasure chests instead of neighborhood-themed treasures.
In an update to the test server, treasures heal more laff points:
3 in Toon Estates,
4 in Toontown Central,
4 in Chip 'n Dale's Acorn Acres
15 in Donald's Dock,
15 in Daisy Gardens,
15 in Minnie's Melodyland,
18 in The Brrrgh,
18 in Donald's Dreamland
The Donald's Dock treasures are the only ones that are not on land, but underwater.