1. Go and this archive java_nokia_n900_maemo5_opera_mini.zip
2. Extract your PC. Inside the folder jre
2. You copy the folder c jre in the folder / home / user /
(I copied to a memory card, and then moved through the MC in / home / user /)
4. Under Root (root) execute the following commands:

cd / home / user / jre / bin /
chmod + x java
chmod + x opera.sh
5. Run a command

. / opera.sh
6. Press ENTER (Start does not work)
7. If the internet (WiFi for example) is not included, turn - the program itself can not yet.

(С) Shadow_ru

more http://maemos.ru/2009/12/20/java-nok...-5-opera-mini/

P.S. Opera Mini is not the only application in Java that can run on the Nokia N900 Maemo 5