Dude, you can recycle now
If your old Dell computers are starting to stack up in the corner of your home, you can actually do something about it now. No, I don't suggest dropping them off skyscrappers. They are computers, not pumpkins!
Dell recently announced that the company is offering a free recycling service for its used computers.. The best part about it is that it's free! You can schedule the pickup right on Dell's website.
Apple offers a similar recycling plan, and surely other computer makers will follow. It's important to note that if you are ditching your not-too-old computer in usable condition, there are organizations that may want it. If that's the case, I'd advise googling for an appropriate location for your old machine. Its final destination shouldn't be on the street.