I thought this bit of VoIP news was quite interesting:
Voiceglo Introduces Linux-based Telephone in a Wireless Wi-Fi Router

Basically, Voiceglo Internet PBX integrates with any Wi-Fi (wireless fidelity) router and can be used with cordless phone systems, analog phone systems, digital phone systems and Wi-Fi- capable PC’s.

If I understand this product correctly, it sounds like this product essentially is IP-Centrex for the small business/SOHO environment. You hook up one of these boxes to your WiFi connection and then you get up 2 – 10 lines in small homes and businesses and up to 254 lines (per Wi-Fi router) in larger scale PBX deployments. Voiceglo acts as the ITSP providing the termination to PSTN phone numbers and charging just $24.99 per month for unlimited calling in the United States and Canada.

Basically Voiceglo takes the Vonage model which has a maximum of 2 lines and extends the reach of VoIP from the residential market (i.e. Vonage & Packet8) to the commercial market - which requires more than 2 VoIP lines/trunks.

Whether or not this product has call transfer or call conferencing is unclear, although their press release mentions "conferencing applications". I checked out their website to find out more info, but this news is so new, I don't even see it listed on their web site.

I would assume since they are calling this "Voiceglo Internet PBX" that it has some PBX features - including transfer & conferencing.