As the name suggests, Shrinkmytunes squeezes MP3 music on a computer so that it takes up less space, and so that more songs can be fitted on a hard disk or a portable music player.

It does this by throwing away things it thinks the human ear can't hear. This results in a lower-quality sound, but in theory, the quality difference shouldn't be too noticeable.

We tested it with six sample tunes, including folk, rock and dance music, using blinded volunteers to listen to the results. We also compared the Shrinkmytunes files with ones compressed down to a lower bit rate by the free DBPoweramp Music Converter.

The Shrinkmytunes versions were a lot smaller in size - our six files went from 36.2MB to 9.4MB using Shrink, while using DBPoweramp they took 10.4MB. It was also reasonably quick, taking three minutes to convert all six files (DBPoweramp took around a minute).

With lower-fidelity music (such as songs that came off a tape or LP, or that weren't well recorded in the first place) such as the folk track, the difference was much less clear, and in some cases, it wasn't possible to tell the difference between the Shrinkmytunes version and the original.

For spoken word and audiobooks, we saw almost no difference at all. With the rock and dance music however, which was better produced and came direct from CD, Shrinkmytunes wasn't so impressive, with most people identifying that file as poorer but being unable to tell the difference between the DBPoweramp and the original.

The software is very easy to download, install and use, with a friendly interface, and at £20 it's not overly expensive. DBPoweramp isn't as simple, and it takes a fair bit of configuring. It also means converting to WMA files rather than the MP3s that Shrinkmytunes makes.

If you're happy to put up with that and do without the friendly front end, though, we'd advise using DBPoweramp. But if you want a simple one-stop-shop for squeezing songs, Shrinkmytunes works.

Vista compatible: Yes