In several themes you can add a custom header image via Appearance > Custom Header (see this post). In iNove you can add an image to the right side of the header via Appearance > iNove Theme Options > “Banner”. Create a 60px high image, upload it via Media > Add New, copy its URL, and put it in the Banner box this way:
<img style="padding-top:10px;" src="IMAGE URL HERE" alt="DESCRIPTION HERE" />
(For a less than 60px high image, increase the padding number accordingly.)
In Grid Focus you also get a small image at the right side of the header: your blavatar (uploaded in Settings > General).
Note: In iNove there’s a way to insert a header image across the entire header. But –like so many other things– it doesn’t work in Explorer, so I’m not posting it* (unfortunately more than 50% of internet users stick to Explorer, just because Microsoft has planted the thing in their computers)…
*Update: See here.
Update 2: for a Custom Design upgrade solution in iNove, see this staff suggestion.
https://wpbtips.wordpress.com/
wordpress tips 
This is a helpful post that I will have to bookmark. Thanks for blogging it. :)
Posted by timethief | February 11, 2010, 06:31Thanks! It’s a simple post, but I thought I’d better publish it, first because few will notice the possibility the way it’s buried in Theme Options instead of Custom Header, second because it needs the padding to improve its vertical alignment. There will follow a similar post for the brandnew Motion theme.
Posted by Panos | February 11, 2010, 12:35I sometimes see people who have follow links (rss, twitter etc) built right into their headers. How do I do that?
Posted by Derek Ouellette | April 1, 2010, 06:56@Derek: If you’re talking about a wp.com blog, then a) in some themes such links are hard coded into the theme, b) in some themes you can take advantage of this possibility (but the owner of WP doesn’t like that, and he’s personally informed us it’s going to be blocked), c) in some themes it may be possible via the paid CSS upgrade (if you’re very good at CSS editing).
But I guess you’re talking about your self-hosted blog; in that case I’m afraid I can’t help: the software is different, as you obviously know, and I’ve got no experience with it whatsoever.
Posted by Panos | April 1, 2010, 17:24The trick to get the banner to go all the way across — I understand your reticence, since it doesn’t work in Explorer, but what does it do? Does it just not appear when viewed in Explorer, or does it mess the page up somehow?
If it’s invisible, I might like to take my chances. (And if you don’t want to post the trick, but are still comfortable sharing it, please email me.)
Posted by boardgameforge | January 5, 2011, 00:40You need to create a 895×53 image (of course it must include the blog title and tagline), upload it via Media > Add New, copy its URL, then paste this in Appearance > Theme Options > Banner:
Should work in IE8, but by now I don’t remember what happens in previous versions: I’m a Mac user, so I can’t readily check things in IE. If you’ve got IE7 please let me know!
Posted by Panos | January 6, 2011, 16:31Thanks for your prompt reply! I’ll have to give this a try soon. :-)
Posted by boardgameforge | January 7, 2011, 01:04I really love iNove theme and used it for my blog http://dotnetfollower.com. But the main problem for me was that iNove theme initially has a much wider sidebar than I need. I’ve reduced the width of sidebar and described it in my article – http://dotnetfollower.com/wordpress/2010/12/get-the-smaller-sidebar-of-inove-theme/
Thanks!
Posted by dotNetFollower | September 30, 2011, 19:08