Hi Suritha,
Based on my experience, I would like to suggest some guidelines from an HR perspective:-
Whatever practice is involved should be replicable, implying that whatever celeberation you do for an employee you should be able to do for all, otherwise if you miss out even one person and do a very good show for the others, that one single dissatisfaction will spoil the whole initiative.
Secondly, timely greeting is more important than the quality of celeberation. Keeping in mind holidays and weekends, you must have a system which ensures that the greeting is given on time.
Thirdly, if your organization has a Pan India presence, how do you organize in the other cities.
Lastly, is your data base accurate and checked with the employee.
Keeping the above in mind, e-cards automatically mailed at mid-night followed by a birthday gift (standardized and non-perishable) e.g chocolates, company momentos etc can be bought and given at a moments notice.. cakes and all require too much of administrative co-ordination.
Please excuse if my mail dampens the celeberation, but since I have worked in large organizations with Pan India presence, have been bugged by these issues at times.
Cheers,
Buland