Improve your Opera Speed Dial experience
Version 9.2 of the Opera web browser added a new feature called Speed Dial. Speed Dial is intended to provide easy access to a user's frequently-visited websites every time a new tab is opened. It is, in short, insanely useful. Like many Opera features (or at least, recently-introduced features), there are customizations that sometimes require a bit of effort to access.
This article will not discuss the basics of adding items to Speed Dial, which is already covered by a video from Opera ASA.
Change your Speed Dial thumbnails
When you add a new item to Speed Dial, Opera will automatically generate a thumbnail of the web page and display that on the Speed Dial interface. Assuming all of your favorite pages are very visually distinct and recognizable when shrunk down, this works quite well. But what if you want to add two pages that look very similar, such as two pages from the same web site, or two pages from different sites that use similar layouts?
Conveniently enough, you can simply replace those thumbnails with anything you like.
The images are stored under your user profile directory. In Windows, they are normally in C:\Documents and Settings\<Your user name>\Application Data\Opera\Opera\profile\thumbnails
If you open this directory, you will find 9 PNG images (assuming you have 9 Speed Dial entries), each 256 x 192 pixels, with seemingly random file names. To change the thumbnails that are displayed, you need only replace these images. For best results, you should use another PNG (required) of the same resolution (recommended). Opera will make a best effort if your image is a different resolution (or a different aspect ratio), but note that it will only shrink (never enlarge) images.
It's worth noting that your images will not necessarily be displayed at their native resolution. They may be shrunk down to accomodate a smaller screen resolution, although the aspect ratio (normally 4:3) will be preserved. This does mean that some images will not render exactly as expected (the 10stripe logo, for instance, renders with some waviness in the 10).
Change the Speed Dial search engine
So that little trick took a lot of space to explain. This one is much simpler.
Tools menu -> Preferences, Search tab, select the search you want, click Edit, click Details, put a check mark next to "Use as Speed Dial search enginge". You're done.
If you want to add a search that isn't shown in that list, you can either use the "Add" button in the Search tab, or use the Create search context menu item.