I am using the Blogger Post Gadget to write this blog post from my iGoogle page.
Here is the Blog Buzz post which explains it further. You can install the feature from here too. Publish to your Blogger blog from iGoogle
This is a nifty tool but, although you can add html the more advanced functions, such as uploading an image, are not available via iGoogle.
PS After you have published your post (or saved it to draft) via iGoogle a "View This Post" link appears so you can come along and look at your post, edit it, as I am doing now, and publish it if saved to draft