I couldn't afford a single mortgage payment at the first of the month, so I wrote two checks each month. I tried to send in a check on the 15th and the other half on the 1st and NationsBank said that I was late because they didn't receive the whole payment on the 1st. For a few years I still wrote the two checks but sent them both in at the same time. Made them cash two checks every month.
After the first year I started to round up to the nearest hundred, which meant I was adding about $40 extra principle every month. (Hey, it was all I could afford). That extra slowly went to $50, then $100, then $200...all extra principle. After about a few years NationsBank and BofA merged and BofA took over the mortgage and I got a new amortization table and I had knocked about 2 years off the end, so I was down to a 28-year (+) mortgage.
When I refinanced, my payments were every two weeks and each payment was roughly equal to what my monthly payment was supposed to be. Basically I was paying the equivalent of 26 "monthly" payments every year.