PSPKrazy has released PSP FTPD v0.01, a simple, but working FTP server for your PSP. With it, you can send files to your PSP without any cables, in Wireless (WIFI). It is based on psppet ‘s networking example and some parts were taken from theno23’s httpd. It is a complete rewrite of a ftp daemon for education purposes. Link.
PSP FTP Server