You mean they look like vertical toothpicks? Probably you have a date axis,
and intermittent (e.g., weekly) data. The axis still has slots for each day,
even if there is no data point, so the columns become narrow. Change to a
category (text) axis.
Excel 2003: Chart menu > Chart Options > Axes tab, select Category under
Category (X) Axis.
Excel 2007: Right click axis > Format Axis > main tab > halfway down, select
Date Axis.
- Jon