Management/Maintenance of WebParts default.aspx?contents=1

Problem: One of your sites, default.aspx page, can't be open... :S cause one unexpected error derived from an Web Part.

Solution: Add this line to your site ?contents=1.
That way you can manage your WebParts in MaintenanceWebPart page.

1- So lets say http://server//site/default.aspx?contents=1
 
2- Remove the problematic or the last Web Part or the one you know that is causing the error.