wow, sounds like us. we've been together over 3 years though, and still aren't sick of each other. :) we also work together (it's just us and his parents in our company), although i only work 2 or 3 days a week. which is good, since it gives me time to run errands, clean house and do whatever i want on my own. ummmm... i'm trying to think of stuff to do. i mean, we're REALLY like you both, and don't do lots of romantic stuff.
i know that going out to eat is a money thing, but we like to go to a relatively cheap mexican place by ourselves sometimes. often when we go out to eat (or to a movie) we go with other people, and thus it becomes a social outing. so it seems sort of special to blow off everyone and get all dolled up and go eat or catch a flick.
if you have the time, take a long drive to somewhere (a scenic spot, a cool shop, a tour of something like an old building or caves or whatever, even a nice restaurant you've never been to). be a tourist in your own state (you *are* in the US, right?) look up free/cheap touristy stuff to do and pick a day to go. i find that we always end up having the coolest discussions in the car for a few hours. if we're just driving somewhere in town we end up talking about mundane stuff or listening to music.
or even be a tourist in your own town (provided it's somewhere with a bit of culture and not bumblefucknowhere like my town). find out when plays and local concerts are. they're usually quite cheap and generally more enjoyable than you might expect.
holding hands and taking a walk together can be nice.
play a board game. it's better than doing nothing, and can be fun, despite it's stigma of being totally dorky.
might not be your thing, but playing video games together can be fun. we're big gamer dorks, and our systems are lanned, so we play against each other a lot. i really love playing co-operative though, which is playing a game and being on the same side. it's nice to have a common goal, even if it's "blow up everything that moves". :)
listen to the radio and make up new lyrics together. cute ones about each other are fun. or turn down the tv volume and make up new dialogue. especially effective with the news.
sorry i can't think of anything more. if i do, i'll be sure to post it. good luck!