Cool, now I definitely don't need a Blackberry!
The standard Series 60 mail client on Series 60 v2 phones such as the 6630 and 7610 works, althought the 6600 does not. The client can be configured for POP over SSL (Mailbox, Settings, Security - On). Although the GMail instructions indicate that TLS is necessary to connect to the SMTP server I didn't find it so when I tried. Of course, Google may change this and implement security at any time.
I tried Profimail last week and it didn't support SSL. This week it does! Well done to Lonely Cat for a quick update.
Whichever method you use, you may get the Untrusted certificate message whenever you connect to the GMail server. I tried two identical 7610's and one happily accepted the certificate and one didn't! If you do get this message then it can be overcome by installing the Thawte SSL Domain certificate. You can downloaded it from here.
Although Mobile Tech were having problems with the GMail atom feed, it still seems to be working for me.