add this to your .htaccess (root)
run a test http://gtmetrix.com before and after the changes and post your opinion.         

 find

 AddType application/vnd.adobe.air-application-installer-package+zip .air
 AddType application/x-shockwave-flash .swf

replace with 

AddType application/vnd.adobe.air-application-installer-package+zip .air

AddType application/x-shockwave-flash .swf

AddOutputFilterByType DEFLATE text/html

AddOutputFilterByType DEFLATE text/plain

AddOutputFilterByType DEFLATE text/xml

AddOutputFilterByType DEFLATE text/css

AddOutputFilterByType DEFLATE text/javascript

AddOutputFilterByType DEFLATE application/x-javascript

AddOutputFilterByType DEFLATE application/xml

AddOutputFilterByType DEFLATE application/x-httpd-php

# BEGIN Compress text files

<ifModule mod_deflate.c>

  <filesMatch "\.(css|js|x?html?|php)$">

    SetOutputFilter DEFLATE

  </filesMatch>

</ifModule>

# END Compress text files

# BEGIN Expire headers

<ifModule mod_expires.c>

  ExpiresActive On

  ExpiresDefault "access plus 1 seconds"

  ExpiresByType image/x-icon "access plus 2592000 seconds"

  ExpiresByType image/jpeg "access plus 2592000 seconds"

  ExpiresByType image/png "access plus 2592000 seconds"

  ExpiresByType image/gif "access plus 2592000 seconds"

  ExpiresByType application/x-shockwave-flash "access plus 2592000 seconds"

  ExpiresByType text/css "access plus 604800 seconds"

  ExpiresByType text/javascript "access plus 216000 seconds"

  ExpiresByType application/javascript "access plus 216000 seconds"

  ExpiresByType application/x-javascript "access plus 216000 seconds"

  ExpiresByType text/html "access plus 600 seconds"

  ExpiresByType application/xhtml+xml "access plus 600 seconds"

</ifModule>

# END Expire headers

# BEGIN Cache-Control Headers

<ifModule mod_headers.c>

  <filesMatch "\.(ico|jpe?g|png|gif|swf)$">

    Header set Cache-Control "max-age=2592000, public"

  </filesMatch>

  <filesMatch "\.(css)$">

    Header set Cache-Control "max-age=604800, public"

  </filesMatch>

  <filesMatch "\.(js)$">

    Header set Cache-Control "max-age=216000, private"

  </filesMatch>

  <filesMatch "\.(x?html?|php)$">

    Header set Cache-Control "max-age=600, private, must-revalidate"

  </filesMatch>

</ifModule>

# END Cache-Control Headers

# BEGIN Turn ETags Off

<ifModule mod_headers.c>

  Header unset ETag

</ifModule>

FileETag None

# END Turn ETags Off

# BEGIN Remove Last-Modified Header

<ifModule mod_headers.c>

  Header unset Last-Modified

</ifModule>

# END Remove Last-Modified Header

On my site, your htaccess adjustment DID increase my speed.

My initial run was 81% and 61%. After the alteration was 82% and 85%.

Most of my score is brought down by image issues. I notice that with my Specify a cache validator, I got a 34. I dont suppose you have any suggestions to bump that higher?

depends what type and how many  images you have try using png instead GIF OR JPG'E  and OPTIMIZE your images will decrease the load time.
Another option would be  combining images using css sprites ( it's a bit tricky )

My initial run was 77% and 79%. After the alteration was 79% and 87%.

I presume higher numbers indicate a positive result  

Pretty cool code, helps alot!

Thanx.
But what's the reason why boonex don't already have this code include? 

I went from 78 68, to 77 69. Actually went DOWN on the first number

78 / 65 to 78 / 68

not really much :(

 "not really much" is better than "nothing".

Before : 61 / 64

After : 67 / 73

Nice one.. ty !

Before:

65 / 63

After:

68 / 65

Not bad :)

80/81 >> 80/93... not sure what it is but i guess a compression of the contents makes a smaller pack demand and therefore faster transfer rate?

The numbers were not much different but my site appeared to be more responsive with the code added... but that may just be wishful thinking on my part. 

Sped my site up allot. Unfortunately, it also caused a problem with remaining logged in. You log in fine but when you go back to the index/home page you find you are logged out. Maybe just a problem with my site but I had to go back to my slower .httaccess to fix the log in.

http://www.boonex.com/forums/?action=goto&topic_id=How-to-reduce-load-time-of-dolphin-7

post on the bottom try that one out.

From 96/82

To 89/80

Old but good 

From 35/64

to 67/75

!!!!!!!!!!!!!!!!!!!!

Very good.

Before 

57-63

After

87-89!

A bit odd though, why I had such low score first as this is pretty much near clean install of 7.1 running on a dedicated server!!? Thought it would be faster than that. Only has 1 user as its still in build!!!

before - 

page load time - 3.02

Total page size - 1.4mb

Total number of requests - 61

after 

2.92s

1.11mb

20!

Thats quite a change with whats actually being pulled from the server...

 I replaced the code but, after that my site shows "Internal Server Error"...