S.W.
My husband and I celebrated our 10th anniversary at university with 4 kids so I understand the no money and no sitter dilemma... What I did was got creative and while he had to work that day, I made up a bunch of poems and clues that went along with everything that I had planned out for the day. Everything that I had planned were things that we had done as dates when we first met. He sent me a yellow rose and a small teddy bear for a valentine the year we met so I had that sent to his office with a poem attached that had a clue for the evening, and basically every hour he would get another clue, by phone or by drop off. Of course his boss was totally in on it and thought it was the neatest thing ever and went right along with it. It gave the kids a chance to see some of the really great things that we did for each other when we were dating too; Some of the sentimental things from our dating days. We had a special dinner together with our children and I rented a projector and we watched a movie on a wall outside with big speakers, kind of like a drive in... one of our first dates... then put the kids to bed and relaxed with some bubbly.......
Totally inexpensive and the memories were more then I can ever replace. It was perfect!