+Zach Glazar and I are going to go through the over 100 suggestions for alternate titles for the Swords & Wizardry: Light "Thief" class. We'll then pick out our 10 favorites, put up a poll and let the readers of The Tavern cast their votes. The top 3 vote getters will then go through a vetting process and one of those three are what we will go with. What's the vetting process? For me it will be "beer and burgers" and bouncing the finalists off my bartender who is a retired detective. I can't speak for Zach's vetting process. It probably involves virtual reality and a distant planet ;)
Now, for those that are wondering, here's the write up for the Swords & Wizardry: Light "Thief". Remember, Swords & Wizardry: Light only covers levels 1 through 3. After that it's expected you will want to move on to Swords & Wizardry: Complete. As such, there will be a full write up of the Light "Thief" for the Complete rules (and I am leaning towards optional rules for S&W: Light that would cover progression through level 7, but that is down the line and would probably not be "official")
The Thief is a figure in the shadows, an expert in stealth and delicate tasks.
Hit Dice: 1HD at 1st Level, 2HD at 2nd level and 2HD+1 at 3rd level
Saving Throw: 15 at 1st, 14 and 2nd and 13 at 3rd
Thieves may wear only Leather Armor. They may use any weapon.
-Thieves start with either Long Sword (1d6) and Dagger (1d6-1) or Club (1d6) and Short Sword (1d6-1) and a suit of Leather Armor AC 12 
Thieves have class abilities as follows:
Backstab: When attacking with surprise and from behind the thief attacks at +4 hit and x2 damage
Hear Sounds: Thieves have a 3 in 6 to hear and identify noise through closed doors
Read Normal Languages: Thieves have a 4 in 6 chance to reads normal languages
Climb Walls: Thieves have a 5 in 6 chance to climb walls and cliffs
Thief Skills: Thieves have a 1 in 6 chance to succeed at Finding / Removing traps, Opening Locks, Picking Pockets, Hiding in Shadows and Moving Silently. Dwarves have a 2 in 6 change to Find / Remove traps, Elves have a 2 in 6 chance to Hide in Shadows / Move Silently and Halflings have a 2 in 6 Chance to Open Locks
*The next bump to the thiefly skills would take place at 4th level and every third level after that when presented for the S&W: Complete rules
** The above write up is subject to revision ;)