.html or .php , - or _ ineed know in title beter "-" "_" and for seo ".html" or ".php" what will the best for seo??? http://dtwallpapers.com/audi_r8_razor_black_wheel-wallpapers.html or ******************/audi-r8-razor-black-wheel-wallpapers.html ******************/audi-r8-razor-black-wheel-wallpapers.php
Use hyphens (dashes, i.e. "-") rather than underscore. (There's a difference to Google between them - test it with ftp_binary and then ftp-binary in search.) It doesn't matter if it's .php, .html or anything else.