A bit long winded but informative I still don't think I want to do it on my Leica, I have several dust spots on it already.
I have done it on my M8 quite a few times - it really is easy and sensors are quite robust
£40 at the photo shop for a 15 min max job
Remember to test it first - f22 pointed at a white wall - have a look at the image in LR and you will see the spots
I also find one of these useful, although I had a problem once at Southampton Airport - they took it off me, (hand luggage), as they said that it could be mistaken for a small bomb or grenade, (but I'm a grumpy old man and told them what I thought of them, so that didn't help!)
When this thread started, i was in the early days of shooting with a DSLR and dealing with dust on the sensor. It seemed pretty traumatic at the time... Now I feel I'm something of a hardened vet and, having incorporated it into the process, it's not a big deal. Although it is a small deal, but one I'm willing to cope with for the other advantages of shooting with the camera that feels like the best overall solution for me.
I have one of those little sticky ended post things and that works brilliantly the vast majority of the time, particularly for quick little spot cleans. I also have a wet cleaning kit (no doubt paid too much, but a price that's worth it to me for the handy nature of it). I just spent about a week and a half traveling, spending time in a sandy, dusty beach environment, and changed lenses in the wild quite a bit. At one point I processed a shot in a way that exposed EVERY dust spot on the sensor and there were a lot of them. I had the little sticky ended bit along with me, and about two minutes with that and the sensor was effectively clean - there were still a couple of minor spots that showed up only in the perfect storm of circumstances, but nothing difficult to deal with. Then when I got home, I gave the sensor a good wet-clean. Probably a 5-10 minute process by the time I'd let it dry, reassemble, do a couple of test shots, and repeat a couple of times to get it really immaculate. What I've found is that if I do that ten minute wet cleaning routine every few months (or after a particularly heavy spell of shooting - I think I've done it three times, maybe four, in the past year), then using the quick little sticky ended thing for spot cleanups in the interim works just fine.
It's one of those things I'd never had to do before with my years of shooting Olympus gear (which is really well known for it's self-cleaning capabilities) and Fuji (which isn't particularly), so initially it seemed like a big deal and a major hassle. But I love shooting the Df and I've found that now that I've done it a few times, it's really not a big deal to keep the sensor reasonably clean and to clone out the occasional spot that makes it through to a visible part of a file. With mirrorless I spent a lot more time charging and swapping batteries (I think with the Df I charged ONE time during that week and a half of travel and heavy shooting over the holidays and I'm not sure I NEEDED to do that, but did it to be safe) - with the Df I spend a few minutes cleaning every now and then. A small price to pay - just another tradeoff...
The biggest problem with dust spots is that they are one of the the most time consuming things to process out of an image. Not so bad if there are only one or two against a featureless sky, but a pain if they show up over or straddling an object. Even sticking to some kind of cleaning schedule didn't work for me because dust can get back onto a sensor the very first time you use it after a cleaning. I was very nervous the first time I cleaned a sensor but it's actually a pretty easy task (I use a Lenspen sensor cleaner which is just like a normal Lenspen but with a small triangular tip). It's a reactive process though so you have to suffer dust spots first before you can remove them.
I've got years of Canon EOS images I'm still working through from cameras both with and without self cleaning mechanisms (which did make an improvement) and all I can say is, sensor dust = pain in the arse