A small mid-afternoon winter procrastination: class.jaiku.php, a PHP5 class to interact with Jaiku.
Update a little later: Once I had all that in place and working, I used the excellent Pashua “give any OS X script a GUI” application to make a primitive “Jaiku GUI”:
It should go without saying that this is all (a) experimental, (b) not exactly “point and click” easy to use because of the requirement of PHP5, which is not installed under OS X by default and (c) not sponsored by or affiliated with Jaiku itself.
Update even a little later: Using Platypus, another excellent OS X utility, you can turn the GUI PHP script into a bona fide “clickable” Mac application. Details in the Rukapedia.