Halflings might seem a bit too "mundane" to be a limited race (although this could be justified by their good abilities/stats and general backround):

Nimble and hearty little folk. Halflings generally prefer to live a simple, happy and peaceful life among their own kind, being mostly unconcerned of the world at large. However, they do possess a certain natural curiosity of all things big or small in the world, and occasionally some of the bolder ones set out on adventures beyond the borders of their land. A few never return, finding more fulfillment in their travels or some other new calling than in the comforts of traditional halfling life, which generally consists of several hearty meals a day with a pint(or two) of ale and enjoying a smoke of fine pipeweed after a day's work in the fields.

Halflings are simple folk who tend to have little affinity for things mystical, and thus produce no true mages. Their heightened resilience and simplicity gives them resistance to magical and mental attacks. Halflings are good or neutral in alignment.

Available classes: thief, warrior, bard, ranger, healer, druid.

Max stats: 17str 20int 21wis 22dex 22con 21cha

Inherent abilities:

- Quiet movement (or sneak, if a greater perk seems more appropriate*)
- Resist magic
- Resist mental
(-maybe also "Jumpy": like the twitchy edge)

- Vulnerable to blunt attacks


* If they were made a limited race, I'd give them sneak instead of quiet mv, and perhaps also tweaking their stats up a bit (mostly wis and/or cha as a bard/priest perk). Also then perhaps even make them good-only, though still able to become druids, as someone else mentioned.