[X-Newbies] Digital Recorder Question

[J]

I am looking at a digital recorder with USB connection such as this one:

http://www.amazon.com/Olympus-WS-320M-Digital-Recorder-Player/dp/ 
B000BJ3BRO/ref=sr_1_5/103-4336298-0031820? 
ie=UTF8&s=electronics&qid=1179020298&sr=1-5

Says it results in WMA format which plays in WMP/or that other thing  
you install on the Intel Macs...but doesn't list Macs although it  
says it can plug into Mac or PC.

Question is, what to use to translate the WMA file to MP3?
And, is non-rechargable battery the only source of power?

I would be using the 22. mode because I don't want huge files to post.

I am looking at this instead of Audi Hijacking my web  
stream...because I want to use it for man on the street as well.