Got the Treo 300 last week and love it.  I was skeptical at first, but everyday I get more addicted to this little wonder.  It surfs the web very well, especially compared to a WAP enabled phone (I've connected 100% of the time so far).  I also have been using it for AIM and it works well in that area too.  I don't use AOL mail, so I can't comment on that.  It costs a lot, but in my opinion, if you can afford it, it's worth every dollar.