See https://wiki.mozilla.org/Mobile/Platforms/Android for system requirements, and an experimental version that might work on your phone.

I tried the Fennec for ARMv6 last night after having to Uninstall Firefox 4 Beta for Andriod. Initially this browser loaded but only as far as rendering a white screen. I stopped trying after about five tries.

Then later the next day I used the installed WebKit to check mail

etc. which this evening (here in Australia) stopped operating altogether and I had to summarily execute an uninstallation. Because the installed browser had stopped operating as the ~search the Web function~. Seemed to be sending / receiving mail from the included gmail app.although if it wasn't updating I guess I wouldn't know as had no further correspondence (I'm sitting in front of my machine now)

Checked the operation of the WebKit installation and it is operating again

Where it says "nightly build" does that mean I should try to download it every night or is it just circumspection that it ~Fennec~ the version changes nightly, slightly?

I downloaded another two (2) nightly builds ~13.08MB~ earlier last week version 2011012403 and version 2011012405 (Access from home screen in 2.1 éclair ->Settings soft key -> select Settings Option -> scroll down to Application Management -> Manage Applications -> scroll down the alphabetical list to Fennec and select for viewing Application info) Both operate the same as above asking every time I wish to open a browser "Complete action using" the installed one or Fennec (managed links etc). If I select the Fennec option (or open it using the short cut widget) it opens a screen with the Firefox in front of the image of the globe and the word "Loading", but then returns to the previous screen I was viewing ??

 There has been no dysfunction with the installed Web Kit so far