Semi-Realistic Resource Pack for Minecraft Frostburn update version that added new blocks and some new sounds.
Semi-Realistic Resource Pack Preview
How to Install:
In order to use HD texture packs properly (32× and higher) you will need to either patch your Minecraft using MCPatcher or using OptiFine. Optifine is preferred as it includes all of the features of MCPatcher, and greatly increases game speeds and graphics settings. MCPatcher tends to be updated on the same day as Minecraft updates, so use it instead if you are in a hurry.
Download links for Semi-Realistic Resource Pack: