anyone ever hiked it? Tips/suggestions on how to train for it?

It's a 10-12 mile hike uphill... it's supposed to be really intense and I'm planning on hiking it at the end of this month. I run 5-8 miles 5/6 days a week and hike on occassion...

I'd suggest backpacking in and camping in Little Yosemite Valley. Do a day hike up and down half dome and then camp again in Little Yosemite Valley.  The mist trail is pretty challenging with a pack so if you turn it into 3 days instead of trying to do it all in one you'll be in much better condition.  No matter the time of year, make sure that you have a waterproof windbreaker at a minimum.  I went camping on May 28th a few years back and a half dome day hiker froze to death from an unexpected snow storm.  6 feet of snow at the base of half dome.

I hiked it when I was 14 with my brothers and Dad.  I was in great shape at the time and had an amazing experience!  It is incredibly challenging if your not used to hiking uphill for that long, so I would definitely suggest doing more of that before going up Half Dome. 

I never necessarily "trained" for it, I was just super active and hiked/camped all the time anyways.  If you havent been to Yomsemite yet, you will love it!  It is absolutely beautiful!  Also, bring a bike if you can . . . the biking trails are lots of fun too . . .

I hiked it about 15 years ago.  I didn't train for it, in fact, I was very overweight and pretty sedentary.  I thought I was going to die and it took me like 10 hours, but I made it.  If you are in good shape, you shouldn't have a lot of trouble, but practice climbing, it is all uphill.

yikes!! Okay I'm scared but I think I'm ready for it.. thanks guys!

I think you are probably ready for it.  I did that hike a couple time but when I was much younger and in better shape.  I actually used to consider myself quite the extreme backpacker going on two week treks with nothing but my Kelty backpack and dirt roll and dehydrated food.  Man, I used to be in such good shape, I can't believe how I let myself go.  But, I digres....

Just pace yourself, enjoy the scenery, BREATHE.  You will be fine!

You are more ready than I was.  I had laparoscopic surgery late april 2006.  I am alight to moderate hiker.  Moderate slopes, 1-2 hour hikes with no backpack, 2-3 times a week at most, 2-5 miles at most.  Because of my surgery I hiked the weekend previous to my Half Dome hike about 8 miles just to make sure I could do distance.  But that was the only hiking I had done for 1 month prior to Half Dome.  I was 32 years old, 160 pounds, 5 ft. tall.  By June 2006 (5 wks post-op/only 1 eight mile hike done since surgery) I did Half Dome, only thinking I was going to go halfway, to the campground.  We left 5:45 am, at the trailhead at 6:00 am.  At the top of Hafl Dome around 2:00 pm.  Back down to the very bottom campgrounds by 7:45 pm, oh and the average temp was mid 80's.  That's longer than most, but I was not very athletic then, and very overweight.  Big musts are hiking socks (Thorlos). All other sock "pill" and give blisters.  Good hiking shoes (for the traction, especially on the rock/cable part).  I also had hiking poles which I never use but found them extremely helpful for my bad knees on the way back down.  I still lost a toenail (which happens) going down.  Didn't even know it happened.  To lighten the load to carry water, I bought a water bottle that had a purifier filter in it and refilled at Vernal Falls (the last water source).  Best tasting water in the world!  

Trust me.  You can beat a 32 year old, overweight girl with not much athletic endurance ahead of time.  You'll probably finish in half my time.  It was worth every minute!

Thanks so much guys, your input is causing my anxiety to go down some. I just think it'd be a great thing to do this summer, one of those things I can brag about to my grand kids some day...

They used to have T-shirts with a picture of half dome and "I made it to the top" written on them for sale in the shops.  After you make it, you have to buy one.  I still have mine.