For starters it doesn't look like you structured your HTML correctly.
Each "column" should be wrapped in its own DIV which should have a corresponding explicit with, you can then float the DIVs side by side (not the h2s)
not only will that get you to what you want , but it will make for more semantically correct HTML. Speaking of which, dont skip headings( since your column heading is h2, then each sample heading should be h3 and not h4.
(edit: I may have misunderstood what you intended to do... if you wanted your web projects to line up horizontally and then your web heading to fall bellow .. ralphs suggestion would suffice)