Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
If your willing to take the time you can get over the air syncing working with iCal, email, and address book without paying for mobile me.

If you think you will use the other features then go for it. The find my iPhone feature doesn't really have any alternatives.
 
It's not cheap, but it's the only email solution I can get my non-computer savvy mother to use correctly. Plus she has an iPhone, so the push and everything works well.
 
I use it all the time, works like a charm and provides an offsite backup for important files. Sure there's other ways to sync/store data but if you're using an iphone the integration is well worth the price imho.
 
Personally, it is great for me to keep everything synch'ed automatically (iPads, phones, PC, Mac). So for me, it is worth it...

And I even paid $99 for it. Now that I learned (here) that it could be purchased on Amazon for ~$60, it is even better when it is time to renew.
 
It's only worthwhile if you have an iPhone. Otherwise, there are better, cheaper ways to back up and sync stuff.

Don't forget your iPad too. ;)

I love mine but that's me. As mentioned you can get it cheaper through other places so you should never have to pay $99 for it.
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.