Here following there are some web resources on phytoliths:
The Missouri Phytolith Database (USA) was set up by D Pearsall and it is one of the best phytolith database for the New World. Easy to search and with reasonably good photos.
The Department of Archaeology, University of Sheffield (UK), has a new Wiki tutorial on Archaeobotany with a section dedicated to phytoliths. This tutorial was set up by a group of European archaeobotanists (Marie Curie Actions - EU) and it is meant to be used together with a taught course in Archaeobotany. However, it is also very useful on its own. The section on phytoliths was compiled by M Madella & D Zurro.
The Institute of Archaeology (UCL - UK) has a good page on Old World phytoliths compiled by DQ Fuller & students/postdocs: Archaeobotany - Phytolith teaching & research images.
T Ball at BYU has an interesting phytolith web page with Old and New World taxa (including banana phytoliths).
M Hodson has a phytolith web page with his most recent work on phytoliths and some good references.
M Blinnikov at St. Clouds University has a phytolith gallery with a lot of good images from wild plants of the Pacific Mid-west.
The Colonial Williamsburg website has a phytolith database with photographs from New and Old World taxa.
The Wits Online Phytolith Database at the University of the Witwatersrand, Johannesburg (South Africa) was compiled by LM Pereira and it has a good collection of South African taxa.
Should you want to suggest more interesting links, please email a note on phy-talk. Thank you.