Maybe I'm late to the party. I probably am, but I haven't noticed this mentioned, and maybe it will be useful to some.
Playing around, I found the "get audio" menu item when looking at an RSS podcast feed in the blackberry browser.
For example, point your internet or hotspot browser to http://detective.rnn.libsynpro.com/rss
Highlight one of the titles, open menu ...
The size of the audio attachment is also shown in the menu.
If anybody else is doing this on the blackberry, I'd be curious what feeds you are following.
I tried the Uncensored History of the Blues podcast produced by the Delta Blues Museum, but the feed doesn't resolve in the blackberry browser.
Just added the John Batchelor Show feed at http://www.wabcradio.com/sectionalRSS.aspx?id=33447
. That works, but curiously the download rate is very slow.