I have very fond memories of using Opera Mini on my N-Gage and on a bunch of later feature phones that only had J2ME support. It felt revolutionary at the time, especially since data plans were still extremely restrictive.
Wifi on phones was also not quite a thing yet, so I had found an application for S60 phones that allowed them to share a computer's connection via Bluetooth. The range was extremely limited, but enough for me to browse the internet from my bed!
I only remember doing the reverse: when the wireless AP at home broke down, I created a Bluetooth PAN to use the cellular Internet connection on my computer. Didn't need to install any J2ME app. (At that time desktop OSes had basically no background process that would use the Internet silently. )
Wifi on phones was also not quite a thing yet, so I had found an application for S60 phones that allowed them to share a computer's connection via Bluetooth. The range was extremely limited, but enough for me to browse the internet from my bed!