[Fixup]

OK, this is the most effective way to speed/clean up Opera Mobile - get rid of all Ads:

Close Opera Mobile and soft reset. Download the attached urlfilter.zip and put the urlfilter.ini to the Opera folder. In my case, it is:

\Windows\Opera9

Now start Opera and be amazed how clean and how fast it is!

You should put this ini file to your desktop Opera 10 folder as well, usually in:

C:\Documents and Settings\UserName\Application Data\Opera\Opera

When you use your desktop Opera, whenever you see a new Ad, you can easily block it with the "Block content" feature. Then you can copy this file back to your Opera Mobile to get rid of these new Ads from your phone as well.

You can find updated blocking list here:

http://my.opera.com/Tamil/blog/ad-block

Now it is no longer so necessary to block flash in user.css, you can mark out that part in user.css like this:

@charset "UTF-8";
/*
Name: 69483
      Block Junk
Version: 1.01
Author: Xin Feng
Description: Block flash, blinking, marquee etc.

Copyright © 2003-2005 Opera Software ASA.
*/
/*
embed[src]:not(.ucContent):not([src*="nicovideo"]):not([src*="ytimg.com"])
{
	content: -o-skin("Attachment Video") attr(src);
	-o-link: "javascript:document.activeElement.className+=' ucContent';void(0);"; 
	-o-link-source: current;
	border: 2px dashed #080 !important;
	font: normal normal normal 10pt sans-serif !important;
	padding: 1px !important;
	display: inline-block !important;
	height: auto !important;
}*/

blink, marquee { 
	display : table-row !important; 
	font-size : 1em !important; 
}