With jQuery there is no need to use SPD or to convert the view. In the following example jQuery will change the width of the two columns "Status description" and "Type of Work" by changing their CSS style attribute.
Start by looking up the HTML markup for the two table headers using View-Source. I'm using jQuery filters that look for the TH elements using a CSS class selector and a content filter. Then add a Content Editor web-part (CEWP) to your page and enter this script in the source editor:
<!--ADJUST TABLE COLUMN WIDTH-->
$("TH.ms-vh2-nograd:contains('Status description')").css("width", "150px");
$("TH.ms-vb:contains('Type of Work')").css("width", "150px");
Note that not all column header text containers are TH elements, that the CSS class name varies by column type and that the jQuery contains(text) selector content filter is case-sensitive. I've also used the shorthand to the $(document).ready() function in the script.
You can also speed up the selector by explicitly specifying the jQuery context, such as the id of an enclosing table DOM element - typically "#MSO_ContentTable". Thanks to Paul Grenier for this tip over at the EndUserSharePoint cross-posting. Also consider using the :first filter to stop looking for elements after finding the first matching column.
Next time, I'll show how to create a frozen header row that will stay fixed even when scrolling.
[UPDATE] As the most common problem people have with this is getting their jQuery selector right, please see this post by Chris O'Brien on useful jQuery tools.