Here's something interesting:
Age: 20-29
Median Net Worth: $7,900
Top 25%: $36,000
Top 10%: $119,300
Age: 30-39
Median Net Worth: $44,200
Top 25%: $128,100
Top 10%: $317,800
Age: 40-49
Median Net Worth: $117,800
Top 25%: $338,100
Top 10%: $719,800
Age: 50-59
Median Net Worth: $182,300
Top 25%: $563,800
Top 10%: $1,187,600
Age: 60-69
Median Net Worth: $209,200
Top 25%: $647,200
Top 10%: $1,429,500
Source: Federal Reserve Board's 2004 Survey of Consumer Finances
Ref:
Free Money Finance: Median Net Worths -- Are You Ahead or Behind?