Send files and folders to your friends. There is no restriction on the file type or size. You can send files using drag and drop in a chat window or by clicking on "Send files". If you share a photo, Google Talk will show a thumbnail so you know how it will look while chatting about it. You can also share folders.
You can think of voicemail as an offline message. If a friend can't answer the call, you can still leave him a message of up to 10 minutes. Or you can directly send a voicemail if you feel it's more appropriate.
The person will receive an email that includes your voicemail as an MP3 attachment or embedded in an MP3 player (24k, 11025Hz Mono):
You can search all the voicemails in Gmail by adding label:voicemail to the query.
Show your contacts what music are you listening. It works with Winamp, Windows Media Player, iTunes and Yahoo Music Engine.
Download Google Talk 220.127.116.11 from Google Talk's site.