An interesting Sudoku variant

I have been away from Sudoku for a year or two, but got lured back when this variant was posted by Kottke this morning.

In this variant the numbers in the dotted "cages" have to add up to the designated total (without duplication within the cage), and the numbers in the "thermometers" have to rise, with the lowest in the "bulb" of the thermometer.  Otherwise normal Sudoku rules apply.

You can play this grid online here, where there are the standard tools for entering "possibles" and for checking the validity of your entries as you go along.  I used the latter feature regularly, and managed to fill in the grid in 64 minutes without blind guessing.