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CLAIMS:

1. A communications system comprising at least one first portable device capable of wireless message transmission and at least one second portable device capable of receiving such a message transmission, wherein the at least one first portable device is arranged to broadcast a series of inquiry messages each in the form of a plurality of predetermined data fields arranged according to a first communications protocol, wherein the at least one first portable device is further arranged to add to each inquiry message prior to transmission an additional data field, and wherein the at least one second portable device is arranged to receive the transmitted inquiry messages and read data from said additional data field.

2. A system as claimed in Claim 1 , wherein the at least one first portable device is arranged to add said additional data field at the end of a respective inquiry message.

3. A system as claimed in Claim 1 or Claim 2, wherein the at least one first portable device is arranged to include an indication in one of said predetermined data fields, said indication denoting the presence of said additional data field.

4. A system as claimed in any of Claims 1 to 3, wherein said first communications protocol comprises Bluetooth messaging.

5. A system as claimed in Claim 4, wherein the at least one first portable device is configured to broadcast a series of inquiry messages on a predetermined clocked succession of frequencies, with clock information for said first portable device being included in data carried by said additional data field. 21

6. A system as claimed in Claim 1 , wherein the at least one first portable device is arranged to include in a message first comparison data, the at least one second portable device further comprising storage means holding second comparison data and comparator means arranged to identify when there is a match between the first and second comparison data and present the data read from the additional data field, otherwise to not present the data.

7. A system as claimed in Claim 6, further comprising means for generating said second comparison data from user profiling of the user of said second portable device.

8. A mobile communication device for use as said first portable device in the system of any of Claims 1 to 7, the device comprising communications components capable of wireless message transmission and arranged to broadcast a series of inquiry messages each in the form of a plurality of predetermined data fields arranged according to a first communications protocol, and to add to each inquiry message prior to transmission said additional data field.

9. A mobile communication device for use as said second portable device in the system of any of Claims 1 to 7, the device comprising a receiver capable of receiving a short-range wireless inquiry message including a plurality of data fields according to a first communications protocol, means for determining when an additional data field has been added to said plurality of data fields, and means for reading data from such an additional data field and presenting the same to a user.

10. A device as claimed in Claim 9, further comprising the technical features recited in Claim 8 enabling said device to further function as said first portable device. 22

11. A device as claimed in Claim 10, further comprising user- operable means for selecting operation as said first or said second portable device.

12. A device as claimed in Claim 10, further comprising control means operable to switch between operation as said first or said second portable device.

13. A device as claimed in Claim 12 wherein said control means is operable to switch between operation as said first or said second portable device at pseudo-random intervals.

14. A method for enabling the user of a first portable communications device to broadcast messages to the users of other portable communications devices, wherein said first portable communications device broadcasts a series of inquiry messages each in the form of a plurality of predetermined data fields arranged according to a first communications protocol, and wherein said first portable communications device adds to each inquiry message prior to transmission an additional data field carrying broadcast message data, such that suitably configured other portable devices may receive the transmitted inquiry messages and read the broadcast data from said additional data field.

15. A method as claimed in Claim 14, wherein the first portable communications device adds said additional data field at the end of a respective inquiry message.

16. A method as claimed in Claim 14 or Claim 15, wherein the first portable communications device includes an indication in one of said predetermined data fields, said indication denoting the presence of said additional data field. 23

17. A communications system comprising at least one portable device capable of wireless message transmission and at least one fixed receiver device capable of receiving such a message transmission, wherein the at least one portable device is arranged to broadcast a series of inquiry messages each in the form of a plurality of predetermined data fields arranged according to a first communications protocol, wherein the at least one portable device is further arranged to add to each inquiry message prior to transmission an additional data field, and wherein the at least one fixed receiver device is arranged to receive the transmitted inquiry messages and read data from said additional data field.