The cats are great for a lot of household tasks that I don't really feel domestic enough or I'm simply too lazy to undertake.
For example, I see no reason to sully my dainty hands doing things like "pressing on a handle" or "pushing on a piece of wood hinged to the wall". So I make Dmitri do it for me.
There are a few kinks to this -- it takes him a few tries to open the door and it's ridiculously loud and sometimes he breaks in when I really don't want a cat in my room -- but on the whole, it's a lot of effort saved for me.
While D assists getting me through portals, Lothar has been assigned a more sentient duty. One of his favorite things to do is open the cabinets and drawers and then sit in side of them; it was only natural that this should progress to guarding the pots and pans.
Lothar is also in charge of decorating; whenever I have a vase of flowers, he always knows just how to rearrange the table for maximum flower petal pizzazz.
While I may idiotically believe that the flowers look pretty inside the vase, arranged and, say, whole, Lothar will fabulously challenge my weak viewpoints by deconstructing ...everything. He makes sure the house doesn't lapse into an old, stale style -- he keeps it hip!
I also put them on laundry duty. Whenever I have clean clothes ready to be worn again, it's nice to know that the cats are there to make sure nothing gets too "pressed" or "furless". Pepin also likes participating in this particular job.
And then there's baking! I love baking. I hate cleaning. Fortunately, I simply employ a cat as a mop and the mess just takes care of itself!!
At last, there is everyone's favorite task. Alarm clocks! No one ever oversleeps here!