How can I use swift in Terminal?

In Xcode 6.1.1 with Command Line Tools installed you can execute scripts by referencing directly to /usr/bin/swift the following way:

#!/usr/bin/swift

let variable: String = "string"
print("Test \(variable)")

sudo xcode-select -switch /Applications/Xcode.app/Contents/Developer

then you can do one of these:

xcrun swift 
lldb --repl

As of Xcode 6.1 - typing swift in the terminal launches the REPL as well.

Alternatively, if you don't want to mess up your current dev environment, you can just run:

/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/swift

Step 1: Open Terminal
Step 2: Type "swift"
Step 3: There's no step 3

Example:

GoldCoast:~ macmark$ swift
Welcome to Swift!  Type :help for assistance.
  1> println("Hello, world")
Hello, world
  2> var myVariable = 42
myVariable: Int = 42
  3> myVariable = 50
  4> let myConstant = 42
myConstant: Int = 42
  5> println(myVariable)
50
  6> let label = "The width is "
label: String = "The width is "
  7> let width = 94
width: Int = 94
  8> let widthLabel = label + String(width)
widthLabel: String = "The width is 94"
  9> :exit

GoldCoast:~ macmark$