In my original post I boil for an hour, but hops in at 30 minutes. The idea of the first half hour of boil is to coagulate stuff from the partial mash that might cause haze in the finished beer, then half an hour of hops. There probably wouldn't be much difference in simply boiling for 30 minutes with the hops. As the hops are boiled in the wort from the partial mash then the length of boil depends how bitter you want the beer. If it's a well hopped kit such as Coopers Real Ale and you are using the hops for flavour and aroma then a ten minute boil would be fine. On the other hand if you are doing something really light in flavour such as a Cerveza kit plus some plain base malt and need a bit of background bitterness, then probably the half hour boil with a small amount of bittering hops (say Magnum or Galena) would be more appropriate as you aren't looking for much aroma, just a bit more bitterness than you would get from the Cerveza or Canadian kits. I did that myself just recently (kegged yesterday) with a "Blonde Ale" partial and a few grams of Super Alpha.