Even though I don't believe IBrowse sucks, it is indeed outdated.
And that FaceBook link does work in IBrowse with a little bit of effort, but it won't work straight away (it will ask you to download the file rather than displaying it).
In any case... what would you expect from such an old, underpowered computer? If like some suggest, you expect to be able to match a brand new PC for the modern web browsing experience, you may be deluding yourself. But if you have realistic expectations and seriously want to explore the online capabilities of the A600, I think you will find there is plenty of fun to be had with one on a weekend as a hobby.
While you may not be able to watch streaming movies, play Flash games or even browse graphical websites (unless you get a rare accelerator), you can still chat on IRC, MSN and Yahoo (via Grapevine and Bitlebee), read newsgroups, send and receive email, download files via HTTP or FTP, explore countless MUDs (the text version of MMORPGs), log into BBSs and more, all on a 2MB A600. You'll even be able to do a couple of those things at the same time in that amount of RAM. But don't expect it to be fast, you'll be experiencing the internet the way it was in the early 90s, which is all you should expect from a computer built in this era.