Wow this must be a late reply after 2 months! I posted on the "Add-on lens" section originally. The Z10 has 43 mm filter size, and I bought the following:
Canon TL-43 1.7X teleconverter for Optura 100
from Comtec.ca, which is only ** CAN$10.43 ** - in fact S&H is actually more expensive than the lens itself!!
This is in fact a Canon camcorder teleconverter, but it works fine with my Z10, vignetting only in the lower 2/3 of the zoom range (but you want to use it in the tele-zoom range anyway). The quality is EXCELLENT - hey it's genuine quality Canon glass!
I also bought the Canon WD-43 0.7X wide angle converter for Optura from Comtec, but I am not too impressed with the increase in field as well as quality of the image.
Still: THEY BOTH ONLY COST CAN$10.43 EACH (about 30 bucks US for me, shipping, tax, everything included for both lenses!!!). They are brandname quality lens at bargain bottom price (cheaper than those third party add-ons)
These are end-of-the-line accessories for discontinued camcorders, and they are running out, so be quick!!