is it possible to set a field to incrementing value?

if you look at the result below i have a ord (order) column witch i use to order my items with. when items are removed or i moved around i need a way of updating the ord value so that it goes up in order 0,1,2,3,4 and dose not skip values. i have done this before with PHP by fetching a result then looping thought it building an UPDATE statement and executing it. is there a way of doing this with SQL?

Code:
SELECT ord, name_raw FROM cat WHERE parent_id = 2  ORDER BY ord ASC;
ord name_raw
0 earrings
0 rings
2 bracelet
3 brooches
6 necklace
8 cuff links

i want to turn the above into:

ord name_raw
0 earrings
1 rings
2 bracelet
3 brooches
4 necklace
5 cuff links