Fancy the idea of anonymous free speech in public places? This inventor thought it would be a great idea to create a sort of mobile

Designed to promote anonymous public speech, One Free Minute allows calls to the cellphone inside the sculpture to be connected for exactly one minute to a 200-watt amplifier and speaker. The results can be empowering, funny, touching - and downright loud. The speech produced by Jolliffe's sculpture can be heard clearly for more than 45 metres.

The 41-year-old Canadian artist created this compelling machine for his master's thesis project at Ohio State University. It's attached to a bicycle for easy movement, and he's taking it on tour throughout the US and Canada.

There's clearly a political aspect to One Free Minute. By creating a tool that allows anonymous free speech in public places, Jolliffe hopes to let activists speak without fear or recrimination at a time when governments everywhere are increasingly vigilant of who is saying what and where.

The sculpture was designed in Rhino CAD, which offers a wide range of visualisation options. Once Jolliffe settled on the look he wanted, he used a process similar to building a wooden boat, creating the shell out of glass fibre and epoxy, and then sanding - lots of sanding. The electronics turned out to be the easy part. Jolliffe assembled the embedded controller by hand, threw in an off-the-shelf car stereo amplifier, a couple of gel cell batteries, a 200-watt compression driver, and a serially controlled MP3 player. The sculpture was ready to make some serious noise.

From the woman who called to say she had pancreatic cancer and wanted to tell her children she loved them before she died, to political ranters, to silly singers, Jolliffe credits them all. "The people who call up and lay their guts on the line, saying what they really think - this piece was built for them and they are the real creators of what is good about One Free Minute." - Bruce Stewart