Lightroom also has a built in database of the common faults (eg vignetting, barrel/pin cushion distortion) of a wide range of lenses. It has a tool that when ticked will automatically "correct" a photo using the lens data in the EXIF header. I use this a lot with my Canon L lenses.
Other edits I do will usually involve exposure corrections. Either the overall exposure or more commonly recovering detail in the shadows and highlights. Lastly, in landscapes, especially if in blueish hazy conditions, I will sometimes either boost the clarity control or reduce the blue luminance to improve distant detail.
Lightroom 4 has just been released and I am pleased to say that in addition to a price cut, the RAW conversion engine has been updated and the editing controls for shadow and highlight are now more intuitive to use and certainly on the few comparisons I have made with Lightroom 3, the algorithm used seems to produce better results. These are probably the two most useful tools in Lightroom and I am pleased to see improvement. Lightroom 4 allows you to choose whether to convert any of your previously edited Lightroom 3 work to the new RAW conversion engine. You can still work with the old version and tools in Lightroom 4 but if you convert to the new expect to have to make some adjustments.
GPicSync to do this but that freeware program took ages to open all the RAW files, so I only used it with small .jpg files I had exported.
Now Lightroom 4 has an extra map screen which allows you to import your GPS unit's .gpx file and very quickly autotag all (or selected) photos with their position. You do need to ensure that the camera is set to the right time so that it is correctly synchronised with the GPS unit's time (which the GPS will get from the satellites). If you forget to do this there is a handy time zone offset slider that will also allow you to compensate if your camera is a few minutes late or fast. This is a great addition to Lightroom, which has speeded my workflow.
All in all, Lightroom 4 has some welcome major improvements, which have made it a worthwhile upgrade for me. If you are not using Lightroom and are still using Photoshop or similar, then do yourself a favour, get yourself a copy of Lightroom 4 now! It is a really excellent program that will greatly enhance your workflow, when you get back from a photo shoot. You will end up with more time to compose and take photos rather than fiddling with them afterwards!
Lightroom 4 is available for Windows PCs and Macs for £103.88 (Upgrade £59.09) free trial available.
Note for Mac users.
Since 1984, I have been ambidextrous, using primarily PCs for home use but using both PCs and Macs at work. Before I retired, I was able to compare Lightroom 3 and Aperture on a well specified Mac Pro (with a Quad-Core processor) using my Canon 5D mk2 RAW files. I found Lightroom 3 to be faster at file handling and previewing and it also has a much more powerful set of editing tools. Lightroom and Aperture use different RAW conversion engines. On my Canon files, the Lightroom converted RAW files look a littler flatter and more natural than the Aperture converted files that look brighter and more contrasty. Some people prefer one over the other. Both programs allow you to adjust the end result anyway but I found that the Lightroom tools work better on my photos. (I found Aperture was less easy to tone down, than Lightroom was to brighten up.)
Given Lightroom's range of effective tools, I think Aperture users would end up using Photoshop much more than Mac Lightroom users. (I hardly use Photoshop since I started using Lightroom.) Aperture also handles the files a different way, wrapping everything into a single database file. Aperture maintains a separate catalogue from the files. I guess that most people brought up on Macs would prefer the Aperture approach but ambidextrous and recent PC converts to Mac probably prefer the greater file control of Lightroom and might not like committing all their photos to a single large file on a (mortal) hard disk's allocation mapping table. (I am still smarting from how little control I have over photo handling in my iPad2, so perhaps I have a slightly jaundiced view of this.) Making the right choice, first time, is important because after you have used one or the other program for any length of time, you will have a lot of cataloguing and editing that you will not be able to transfer. It's a bit like camera systems, once you have bought into Canon or Nikon...
Anyway I recommend that Mac users should also try Lightroom 4 for themselves, it is a great program and it is available as a free trial download for Macs.