[kpayne]

First, set the "products per row" in your appearance preferences. Then you need to edit skin1/customer/main/products.tpl, find this code:

{if $usertype eq "C" and $config.Appearance.products_per_row ne "" and $config.Appearance.products_per_row gt 0 and $config.Appearance.products_per_row lt 4 and ($featured eq "Y" or $config.Appearance.featured_only_multicolumn eq "N")}

And change it to this:

{if $usertype eq "C" and $config.Appearance.products_per_row ne "" and $config.Appearance.products_per_row gt 0 and $config.Appearance.products_per_row lt 100 and ($featured eq "Y" or $config.Appearance.featured_only_multicolumn eq "N")}

The cart checks to make sure you do not have less than one or more than three columns. This code change makes it check for between 1 and 99 columns.

(This is untested, but should work with no problems)