Yes are upgrades, but they are provided by your carrier. For example: At&t has texted me when the 2.2 FROYO upgrade came out for my phone, the Samsung Galaxy S: Captivate. The upgrade process probably took me approximately 45 minutes.
Follow the link in the text message and it takes you to a website with pages filled with instructions. It is kind of complicating, but it's possible to do it yourself.
I don't think there are any hacks, at least none that I know of. I really don't think it would be worth it to hack your phone, especially because you lose your warranty. There will always be OS updates in the future, but you only get ONE warranty.
You can root most Android phones and there are a huge selection of custom 'ROMs' for supported phones.
OTA updates for the latest softwares are usually filled with crap and very late to your phone. Check out xda-developers forum for more information, AfterDawn isn't the place to be asking about this.
