to qualify for google adsense for domains/domain park you need to have a few nice domains generating around 750k impressions per month but i am pretty sure you will get accepted if you have slighly less if you just make a little "typo" when you first submit your application
http://www.google.com/domainpark/faq.html
..and what do you mean passport.net was sold? according to whois records from as far as i could locate over at whois.sc they always owned that domain;
Domain: passport.net
Cache Date: 2001-12-11
Registrar: NETWORK SOLUTIONS, INC
Registrant:
Microsoft Corporation
One Microsoft Way
Redmond, WA 98052
US
Domain Name: PASSPORT.NET
Administrative Contact:
Gudmundson, Carolyn Email protected from Robots by Whois Source
Microsoft Corporation
One Microsoft Way
Redmond, WA 98052
US
+1 (425) 882-8080 +1 (425) 936-7329
Technical Contact:
MSN NOC Email protected from Robots by Whois Source
Microsoft Corp
One Microsoft Way
Redmond, WA 98052
US
425 882 8080
Fax- PATH
Record last updated on 11-Dec-2001
Record expires on 13-Aug-2011
Record created on 13-Aug-2001
Domain servers in listed order:
TUK2-DNS-1.SEA.MSNGLOBAL.NET 207.68.179.63
TUK1-DNS-1.SEA.MSNGLOBAL.NET 207.68.181.114
NS1.HOTMAIL.COM 216.200.206.140
NS2.HOTMAIL.COM 216.200.206.139
NS3.HOTMAIL.COM 209.185.130.68