After Processing Resources
If keeping track of your photos are not your primary aim then you really don't need Lightroom.
Lightroom is a database first and foremost. Added to the database are some other things like simple image editing capabilities, printing, direct to Web, GPS mapping, and slide show, but it is still first and foremost a database. The more images you have, the more you should have a photo database like Lightroom.
Photoshop comes with the free add-on called Adobe Camera Raw. This add-on is to all intents and purposes the same as the Develop module of Lightroom and can be used to do all the image editing that is in Lightroom. It is normally for RAW format images but can be used for any image format.
If you want to know more about Photoshop for editing images or about Lightroom then watch the free Adobe tutorials.
Living and loving it in Bangkok, Thailand. Canon 7D - See the gear list for the rest.