I have been making jams for 20 years, but until today I had never heard of not using pectin to make it jell.  Well, I found a recipe on Epicurious that has made me a believer (at least for raspberry jam).  It jelled just great and has the most intense raspberry flavor I have ever encountered outside of a pie.  I varied the recipe only slightly, using 5 cups of raspberries and 3 cups of sugar.  I used the water bath method of processing and processed for 12 minutes due to the altitude.  Here is the link to the recipe.

Old Fashioned Raspberry Jam