If you enable Gzip compression by changing .htaccess, you can speed up Magento significantly. Assuming that you have Gzip enabled on your server. Uncomment the part of the code in your htaccess file that matches the code below. You uncomment by removing the #.

############################################
## enable apache served files compression
## http://developer.yahoo.com/performance/rules.html#gzip

# Insert filter
SetOutputFilter DEFLATE

# Netscape 4.x has some problems…
BrowserMatch ^Mozilla/4 gzip-only-text/html

# Netscape 4.06-4.08 have some more problems
BrowserMatch ^Mozilla/4\.0[678] no-gzip

# MSIE masquerades as Netscape, but it is fine
BrowserMatch \bMSIE !no-gzip !gzip-only-text/html
# Don’t compress images
SetEnvIfNoCase Request_URI \.(?:gif|jpe?g|png)$ no-gzip dont-vary

# Make sure proxies don’t deliver the wrong content
Header append Vary User-Agent env=!dont-vary

# enable resulting html compression
php_flag zlib.output_compression on