Today, I did not longer want to do "dry" practicing and I searched on google in order to find some accompaniments for my standard repertoire (Swan, Vocalise, G-String Aria). Finally I discovered a wonderful website where one can get high quality mp3 files with piano accompaniments, much better and with more musicality than most midi files. OK, they charge a few British pounds for the download, but it's worth.
See here:
http://www.piano-accompaniments.com
See here:
http://www.piano-accompaniments.com