I have a tiny little book, about the size of an in-purse address book. It's easy to take with me and if I'm at home, I take it out of my purse or school bag and keep it near my desk so that it's right there staring at me. If you memorize or make a list of your common foods and their point value, then you can take that with you as well and use it throughout the day at work without hauling all your stuff around with you. Or, if you are planning your meal ahead of time, write it in the book and take it with you so that you know before you eat how many points you'll be using. I do this sometimes too, if I pack my lunch the night before and take it with me. It is really working for me, and I haven't missed a day journaling since I started using it!
Whatever you decide to do, I'm sure it'll work for you
I think WW has a little electronic points calculator too. Or they do here, anyway, so I imagine they would in the US too. It stores up to 7 days worth of points in it I think.