Code:
@ echo off
"C:\Program Files\Java\jre6\bin\javaw.exe" -Xmx1024M -Xms512M -jar "C:\...\Minecraft.exe"
pause
This is for allocating memory when you start up your Minecraft client. Put it in a text file and if you are using Notepad, switch the file type to all types and change the name to file.bat to make it a batch file (name it w/e you want). For those that use other programs like Notepad++, just switch the file type to batch(.bat) if available. The 1024M is the amount of memory you are allocating, which in this case is 1024 megabytes, aka 1GB. You can do this in gigabytes as well by putting 1G instead of 1024M.
In regards to the 2 filepaths listed, this is where your javaw.exe file is and where your Minecraft.exe is. Change this appropriately for your operating system and the location of your files. The first filepath is if you are using 64-bit java. If you run 32-bit java, switch this to Program Files (x86), or leave it as is if you run a 32-bit OS. For those running 64-bit OS with 32-bit java, consider installing the 64-bit version of java as it might work better for you whenever you have something that is capable of using it.
The code above is for Windows users, but you can make similar scripts if you are either a Linux or Mac user. If anyone one needs help with this, feel free to hit me up and I'll see what I can do.