htaccess mod_rewrite缩短为SEO友好URL

Question

I have this address

http://www.nfrases.com/tag.php?id_tag=10&id_frase=508

that I would like to make it a lot shorter and more SEO friendly to something like (I don't know ... open to suggestions) http://www.nfrases.com/tag/10/508 or http://www.tag10name.nfrases.com/508

I need help with how to code this, because a simple thing as trying to make the address always http://www.nfrases.com case the user goes to http://nfrases.com or www.nfrases.com I tried and failed :(

Used this code by the way:

Options +FollowSymlinks
RewriteEngine on
RewriteCond %{HTTP_HOST} !^www.nfrases.com$
RewriteRule ^(.*)$ http://www.nfrases.com/$1 [R=301]

Answer 1

http://www.nfrases.com/tag.php?id_tag=10&id_frase=508

becomes

http://www.nfrases.com/10/508

with this in your .htaccess

Options +FollowSymlinks -MultiViews
RewriteEngine On

RewriteRule ^([0-9]*)/(.*)/?$ /tag.php?id_tag=$1&id_frase=$2 [L,QSA]

Untested. Let me know if it works for you.