At the writing of this answer (11/2010), there is only one generation of Yaris. Until the second generation is introduced, this should be accurate. 26" drivers side, 14" passenger side and a special 12" rear. Be sure to always lookup the exact part numbers for the brand of wipers you decide to purchase by asking the clerk, using the book, or by looking it up online. This not only ensures the correct lengths but also the correct attachments. FYI - there are over 22 wiper arm attachments out there - so its not only length but also attachment. See related links below.
According to my reference, there was no 2004 Toyota Yaris but there is a 2004 Toyota Echo. (The Yaris replaced the Echo in 2006). See sources and related links below.
The 2003 Toyota Echo (yaris) takes 22" drivers and 14" passenger side wiper blades. See sources and related links below for more information. Since there are over 22 different wiper arm attachments, do not buy wipers just by length only. Be sure to lookup exact wiper blade part numbers by vehicle make, model and year for the brand wiper you decide to purchase. This ensures correct length AND correct attachment.
19" & 17"
The 2003 Toyota Echo takes 22" drivers side and 14" passenger side replacement windshield wiper blades.
32 inch
19 and 21
The 2000 Toyota Avalon requires wiper blades in two different sizes. The driver's side needs 24 inch blades, while the passenger side needs 17 inch blades.
The 2007-2010 Toyota Camry takes 24" driver side and 20" passenger side replacement wiper blades.
The 2002-2006 Toyota Camry takes 24" driver side and 19" passenger side replacement windshield wiper blades.
The 2004-2008 Toyota Solara takes 24" driver side and 19" passenger side replacement windshield wiper blades.
All 2002-2008 Toyota Corolla takes 24" driver side and 18" passenger side replacement windshield wiper blades on the front.
The 1999 Toyota Corolla takes 20" driver side and 18" passenger side wiper blades.