JAMMNROSE  I am one of the developers of Neverball and can shed some light on the issue.

We have two download mirrors, caffeinatedcontent.com and icculus.org, which users are transparently redirected to... I did just try downloading from both servers and they seemed to both be fast.

All I can say is click the download link on the site, if it's going slow, cancel and retry until you get it going faster (different mirror)...

It also could be due to some server maintenance that happened recently.

If anyone else has issues, please reply and try to include which mirror it was coming from.  
(Version 1.5.2)

JAMMNROSE  Neverball v1.5.1 has been released (http://neverball.org/). The version here is shown as 1.5, but the download link seems to work correctly, downloading v1.5.1.  
(Version 1.5)

JAMMNROSE  Hey,

I'm the guy in charge of the Mac packaging, we released a silent bugfix that *should* fix this problem. (Scripts failed under 10.4 for some reason.)

Find it here:

http://neverball.org/download.php

Hope you get it running okay!  
(Version 1.5)