Logan J. Kleinwaks of Virginia is one of Jewish genealogy's rising stars. He's involved in OCR (optical recognition technology), as well as Holocaust issues, and has developed several websites, such as ShoahConnect.
He is also great at locating interesting and useful items for Jewish genealogists. Here are late 19th century and early 20th century gravestone inscriptions from Frankfurt am Main and Prague in two volumes he discovered through Google Books.
Caution: These links will show a "download" or "read this book" button in the US, but perhaps not in all countries. In the past, there were some books he recommended but I could not download them in Israel because of certain copyright issues. In this case, I could not access the Frankfurt book, but was able to download the Prague book.
Rabbi Marcus Horovitz's 1901 Die Inschriften des alten Friedhofs der israelitischen Gemeinde zu Frankfurt a. M., containing thousands of gravestone inscriptions from Frankfurt, is viewable here.
PRAGUE, CZECH REPUBLIC
Gal-Ed. Grabsteininschriften des prager isr. alten Friedhofs mit biographischen Notizen, ed. Koppelmann/Kalman Lieben (M. J. Landau, Prague, 1856), containing gravestone inscriptions from Prague, is viewable here.
Although the name lists and text are in German Gothic, with inscriptions in Hebrew, it wasn't difficult to decipher the names.
For more on Kleinwaks, read this recent posting: