What is the biblical basis for Postmillennialism? Related:
  
  
  What are the differences between the different millenialisms?
  What is the biblical basis for Historical Premillennialism?
  What is the biblical basis for Dispensational Premillennialism?
  


Since my previous two questions on Premillennialism were nicely answered, it's time for the next one:

Postmillennialism is a view of the end times that basically says that things will get better and better, more and more (to eventually almost if not all) are converted, and the church expands. This period (which we are in now) is the millennium, and after it is over (i.e, after the world is almost completely awesomeified), Christ will return. (postmils: correct me if I err in my description).

What is the biblical basis for this belief? Also, what logical deductions that support this belief can you make from biblical passages? 

It seems the strongest arguments are in favor of Premillennialism, as there are several passages about the tribulations that will happen to Christians, and I'm not aware of any "Fear not, the world's gonna get awesome!" verses, so what's the reasoning behind Postmillennialism?

If tradition can be a convincing argument, feel free to use it.
Enjoying God Ministries (which I don't know anything about other than the page I will link to) has this summary: The Postmillennial View of the Kingdom of God. They list a number of Biblical quotes which, for completeness, I will add here:

Old Testament: Num. 14:21; Psalms 2:6-9; 22:27-28; 47; 72:8-11; 110:1-2; 138:4-5 (cf. 102:15); Isa. 2:2-4; 9:6-7; 11:6-10; 45:22-25; 65; 66; Jer. 31:31-34; Daniel 2:31-35; Zech. 9:9f.; 13:1; 14:9.
New Testament: Matt. 13:31-33; 28:18-20; John 12:31-32; 16:33; 1 John 2:13-14; 3:8; 4:4,14; 5:4-5; Acts 2:32-36,41; Rom. 11:25-32; 1 Cor. 15:20-26, 57-58; Hebrews 1:8-9,13; 2:5-9; Rev. 2:25-27; 3:7-9; 7:9-10; 11:15; 19:11-21.

One of the more interesting quotes (repeated on monergism (again, I have no other knowledge of the site)) is Psalm 22:27-28:

All the ends of the earth will remember and turn to the LORD, and all the families of the nations will bow down before him, for dominion belongs to the LORD and he rules over the nations.

Personal notes:
The verses I've checked so far, like Psalm 22:27-28, could also be pre-millennialism. I don't see any post-millennialism specific verses. The closest I could find is Matthew 28:19:

Therefore go and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit.

And the second closest is probably John 12:31-32:

Now is the time for judgment on this world; now the prince of this world will be driven out. But I, when I am lifted up from the earth, will draw all men to myself.

To put it more simply: I was a pre-millennialist before I started this study. Now I'm a definite pre-millennialist!
(Another, Psalm 47 appears to be more about military conquest and though it has verses that could be interpreted as millennial, they could just as easily be pre-millennial.)