Google have launched a free software tool you can use to manage your Adwords campaign from your desktop, although you need to apply to use it at the moment as it is in BETA:

http://services.google.com/adwordseditor/index.html

Personally I use Adwords Dominator as it provides some great features above and beyond anything else out there. For example you can see ads you previously deleted so you don’t go and try the same ad text again when your split testing!