http://www.smartphonemag.com/forum/topic.asp?TOPIC_ID=19114

Q: Can I use CF phone (GSM/GPRS) cards in my CF II slot-enabled (meaning not an old Jornada) Pocket PC? Do they offer 3G? A: This is a very common question (see for example this, this, this, this, this and this thread); this is why I'm devoting an entire blog entry to it. You can - the current CF phone cards all support WM2003SE. It's another question whether it's worth purchasing these cards at all. Personally, I wouldn't waste any money on them because the functionality they offer is FAR inferior to any separate (cheap) BT phone (for example, the Sony-Ericsson t610 - my favourite GSM phone -, which is even cheaper than these cards; still, offers much better talk time, much better mobility, BT headset support and, in general, much better everything. And I haven't even mentioned the even better phones like, for example, the Nokia 6230 (lowest price $260 at PriceWatch), which is GPRS Class 10 and EDGE...).

Q: Are there any TV/radio receiver and mobile phone cards that send their sound through the PDA, and not only their built-in headphone socket?

A: Unfortunately, TV/radio receiver cards suffer from the same problem as GSM/GPRS phone cards (see for example this thread on them) – they aren't able to send over analogue (not digitized) sound on the CF (SD) bus.