A colleague asked me about all the options for audioblogging, and it's a bit fiddly to go back through the various postings and find them all so here's a summary of what I've tried.
A long post about different avenues to audioblogging is here.
In summary, you have these choices:
1) record audio yourself and embed it in the page with html. See http://mikecogh.blogspot.com/2005/02/how-to-embed-audio-in-blog.html
2) use the free service provided by http://www.audioblogger.com/. This requires a call to a US number and your post is automatically posted in your blog.
3) use the paid service provided by http://www.audioblog.com/. It's about $8/month. They have a free 7 day trial at the moment. They provide the code and you paste it into your blog. This is the one I would choose but I had trouble with it and so I now use
4) Instant Audio. It's quite a bit more expensive (about US$20/month), but it's a really good service, and you can send audio postcards, post via pc recording or phone (they have a number in NSW), and they have those nice little buttons! They offer a $1 trial for one month. Both Audioblog and Instant Audio also have a companion videoblog service for extra cash.
Note: to use any of these you have to have a standard blog to start with (eg Blogger.com). So audioblogging is actually done within a standard blog.