I'd like to know if it's possible to listen to those cellphone recorded files that have the extension AMR with foobar2000.

If the answer is no, what do you suggest to listen them at my computer?

Not sure about foobar, but this page could be helpful:
http://www.miksoft.net/mobileAMRconverter.htm

Thanks for the link, but I'd still like to be able to listen AMR in Foobar2000 directly, with tags. The worst is having to wait, and having to re-compress to another format to have something practical consedering its size.

if there's someone with skills, I'll be glad to have that plugin

I think I have listened to amrs with mplayer. Try this handy mplayer GUI, MPUI

Or maybe the other omniplayer, VLC, has added support for amrs?

oh, even Media Player Classic plays AMR files! Thanks for the suggestion Demetris.

I'd still like to listem them with foobar though

Since "Mobile AMRconverter" needed a lot of clicking to get it going, I repacked the converter.exe with lame.exe and made another program that converts to MP3 with just a right-click.

You can get it here