I use Blogger with Picasa exclusively. This should work like it used to back in the "Hello" days where you could send a stack of captioned photos to your blog in 1 swoop. Thus photoblogging became awesome.
Picasa has an annoying "feature" where you can only send 4 images at a time, per post, to your Blogger account. After suffering through tons of manual photo re-sizing while on the road in Europe in 2007, and multiple crazy length posts with like 30 photos since then, I've FINALLY found a good solution to solve this issue.
You still can't caption them, but this is close enough!! Saves literally hours of wasted time selecting 5 images at a time manually, and hoping they get into the document correctly, pretty amazing stuff!!
The secret is: get a Mail2Blogger Blogger email address. This is an email address with automatically converts your message (and photos) to a draft post in Blogger. So you select all the images you want in Picasa, and Picasa resizes your images to 800x600, then it uploads the whole lot of them with room for captions. This is an amazing discovery because it'll save me ages of time on my next trip. Great stuff!!