[HTC Sensation] Skipjacks:
I have personally confirmed this to be working on the original and updated firmware!! So no matter what you've done to your Sensation, this should work.

All this hooking up the phone to a computer to flash a new splash screen through fastboot or packing PM85IMG.zip files with a new splash is all WAY more complicated than this needs to be. I detailed this out in another splash screen thread but it's buried in the thread and I want people to be able to have easy access to this information.

You can keep various splash screens on the phone ready to be switched as the mood strikes you when you're out and about since almost 1 click access.

Here's what you do.

Creating a new Splash Screen...

First you have to make or get new splash screens. You can get them pre made all over this forum. If you make your own, convert them to img files using these instructions.

Now that you've got fancy splash screens to play with....

Create a directory on your SD Card called "splashscreens" (Or whatever you'd like to call it). This is just a place to store your splashes.

Put all of your *.IMG splash screen files there. Just be sure to name them descriptively since you won't be able to view them in img format. So if you have a splash screen of the Joker, call the file Joker.img and the splash screen of Batman as batman.img so you know which files are which. You get the idea.

Got that part? Great. You're halfway home. And you're all set up already for the next time too!

Flashing a new Splash Screen to your phone...

Now download an app call GScript from the market. It's free. All it is is basically a terminal emulator that saves scripts so you can run them off a menu instead of typing them out each time. (Brilliant, huh?!)

Save the following line as a script. Make sure it's EXACT.

dd if=/mnt/sdcard/splashscreens/custom.img of=/dev/block/mmcblk0p14

Be sure to check that this GScript script needs SU access. (There's a box to check)

Now run it, and it'll find that Joker.img that you renamed to custom.img in your splashscreen directory and flash it to the right place in the phone.

Want to use another image tomorrow? Just rename custom.img back to joker.img so you'll know what it is next time, rename the new image file to custom.img. Go back to GScript and click your saved splash screen flashing script and boom! New splash screen. Go you, you're more awesome than your friends!

If you type the script in right the first time, it's 100% idiot proof the next 1000 times.

Warnings...

Do NOT use this script on other devices. Another device will keep the splash screen in a different spot and you might flash your splash screen over top of something far more important. The method should work on at least most HTC devices, but the exact location will be different for most. For example it's blk16 on the MyTouch 4G.

The images for flashing still have to be properly formatted as 960x540 IMG files. You can use the other tools linked earlier in this post for that. This won't magically make any old 200x200 JPEG into an awesome splash screen.

If you botch it, it's not my fault. I literally just did this seconds ago and it works like a charm if you do it right.

And if this is still too much for you, look up BootFlash on the market. For 99 cents it apparently does everything for you. (But it's not nearly as nerdy!)