Pendolino is a type of
train that uses (as the name suggests)
tilting train cars (see
tilting train). The system was designed by
Fiat Ferroviaria in late 1960s and was tested in
Italy; currently it's being also used in
Switzerland,
Finland,
Spain,
Portugal and
Czech republic, and coming to
UK,
Germany and
Malaysia. Many models were designed.
The train tilts up to 8 degrees and has top speed of about 250 km/h. While it's not exactly a bullet train, it has several advantages: It's very fast (compared to conventional railway, anyway), inside the cars it's very very quiet, and Pendolino also works on "normal" track (achieving lesser speed, though).
I've been aboard one once (a Pendolino S220). In Finland, Pendolinos were initially deployed in 1995 in southern Finland (to supplement the InterCity trains going between Helsinki and Turku), and went through some fixing due to our harsh winter climate (well, harsh compared to Italy, I suppose =) recently, the Pendolino routes became available on northern parts of the country, and I took one trip from Oulu to Tampere. Yes, it's very quiet (As we were reaching the steadily lethal speed of 140 km/h, the speed that could be achieved on normal track, one of the kids just said "this is a boring train!") and a pleasant way to travel.
Sources: http://www.madeinfiat.com/marapr98/briefa.htm
http://www.railway-technology.com/projects/finland/