Google App Engine Blobstore API experience

I have been building a small website in the past few days using Google App Engine. During this small project, the most intriguing part is hacking Blobstore API. Luckily, I conquered it again and found a few things:

1. To create your own blob in blobstore, you'd better follow this example
2. If you follow that example exactly, you will create a blob without filename. To set the filename when creating a blob, I found this discussion; the original google api document isn't very helpful on that. To get more insights about that API, check the source code here.